chore: set permission levels to read and pin specific commit hashes

.github/dependabot.yml

@@ -0,0 +1,10 @@
+---
+version: 2
+# update once a week, with a 7-day cooldown
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+    cooldown:
+      default-days: 7

.github/workflows/main.yml

@@ -1,4 +1,6 @@
 ---
+permissions:
+  contents: read
 name: main
 concurrency:
   group: ${{ github.head_ref || github.run_id }}
@@ -22,8 +24,10 @@ jobs:
           - '313'
           - '314'
     steps:
-      - uses: actions/checkout@v4
-      - uses: prefix-dev/setup-pixi@v0.9.4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4.3.1
+        with:
+          persist-credentials: false
+      - uses: prefix-dev/setup-pixi@a0af7a228712d6121d37aba47adf55c1332c9c2e  # v0.9.4
         with:
           pixi-version: v0.65.0
           cache: true
@@ -35,7 +39,7 @@ jobs:
         run: pixi run -e tests-linux-py${{ matrix.python-version }} tests-with-cov
       - name: Upload coverage report.
         if: matrix.python-version == '312'
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@b9fd7d16f6d7d1b5d2bec1a2887e65ceed900238  # v4.6.0
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
   run-tests-win-and-mac:
@@ -52,8 +56,10 @@ jobs:
           - '313'
           - '314'
     steps:
-      - uses: actions/checkout@v4
-      - uses: prefix-dev/setup-pixi@v0.9.4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4.3.1
+        with:
+          persist-credentials: false
+      - uses: prefix-dev/setup-pixi@a0af7a228712d6121d37aba47adf55c1332c9c2e  # v0.9.4
         with:
           pixi-version: v0.65.0
           cache: true
@@ -67,8 +73,10 @@ jobs:
     name: Run tests on ubuntu-latest with plotly < 6
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: prefix-dev/setup-pixi@v0.9.4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4.3.1
+        with:
+          persist-credentials: false
+      - uses: prefix-dev/setup-pixi@a0af7a228712d6121d37aba47adf55c1332c9c2e  # v0.9.4
         with:
           pixi-version: v0.65.0
           cache: true
@@ -89,8 +97,10 @@ jobs:
           - '313'
           - '314'
     steps:
-      - uses: actions/checkout@v4
-      - uses: prefix-dev/setup-pixi@v0.9.4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4.3.1
+        with:
+          persist-credentials: false
+      - uses: prefix-dev/setup-pixi@a0af7a228712d6121d37aba47adf55c1332c9c2e  # v0.9.4
         with:
           pixi-version: v0.65.0
           cache: true
@@ -106,8 +116,10 @@ jobs:
     name: Run code snippets in documentation
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: prefix-dev/setup-pixi@v0.9.4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4.3.1
+        with:
+          persist-credentials: false
+      - uses: prefix-dev/setup-pixi@a0af7a228712d6121d37aba47adf55c1332c9c2e  # v0.9.4
         with:
           pixi-version: v0.65.0
           cache: true
@@ -123,8 +135,10 @@ jobs:
     name: Run mypy
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: prefix-dev/setup-pixi@v0.9.4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4.3.1
+        with:
+          persist-credentials: false
+      - uses: prefix-dev/setup-pixi@a0af7a228712d6121d37aba47adf55c1332c9c2e  # v0.9.4
         with:
           pixi-version: v0.65.0
           cache: true

.github/workflows/publish-to-pypi.yml

@@ -2,13 +2,17 @@
 name: PyPI
 on: push
 jobs:
-  build-n-publish:
-    name: Build and publish optimagic Python 🐍 distributions 📦 to PyPI
+  build:
+    name: Build distribution
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4.3.1
+        with:
+          persist-credentials: false
       - name: Set up Python 3.12
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065  # v5.6.0
         with:
           python-version: '3.12'
       - name: Install pypa/build
@@ -24,8 +28,25 @@ jobs:
           --sdist
           --wheel
           --outdir dist/
-      - name: Publish distribution 📦 to PyPI
-        if: startsWith(github.ref, 'refs/tags')
-        uses: pypa/gh-action-pypi-publish@release/v1
+      - name: Upload distribution artifacts
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f  # v7.0.0
+        with:
+          name: dist
+          path: dist
+  publish:
+    name: Publish to PyPI
+    if: startsWith(github.ref, 'refs/tags')
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+    steps:
+      - name: Download distribution artifacts
+        # yamllint disable-line rule:line-length
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c  # v8.0.1
         with:
-          password: ${{ secrets.PYPI_API_TOKEN_OPTIMAGIC }}
+          name: dist
+          path: dist
+      - name: Publish distribution to PyPI
+        # yamllint disable-line rule:line-length
+        uses: pypa/gh-action-pypi-publish@ed0c53931b1dc9bd32cbe73a98c7f6766f8a527e  # v1.13.0