chore(deps): Pin dependencies (#69)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://redirect.github.com/actions/checkout) | action | pinDigest |  → `de0fac2` |
| [actions/setup-python](https://redirect.github.com/actions/setup-python) | action | pinDigest |  → `a309ff8` |
| [docker/setup-buildx-action](https://redirect.github.com/docker/setup-buildx-action) | action | pinDigest |  → `8d2750c` |

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Author: cq-bot

.github/workflows/lint.yml

@@ -12,9 +12,9 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           python-version: "3.14"
       - name: Install dependencies

.github/workflows/unittests.yml

@@ -14,12 +14,12 @@ jobs:
       contents: read
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
       - # Required for the package command tests to work
         name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           python-version: "3.14"
       - name: Install dependencies