Update nix flake inputs structure and add dependency update workflow for rv-nix-tools (#4109)

This pull request adapts the nix flake inputs structure regarding
`nixpkgs` and `rv-nix-tools`. In particular, `nixpkgs` is now specified
for inputs and transitive inputs by following an explicitly specified
revision of `rv-nix-tools`. More thorough reasoning for this change is
outlined in documentation added by this PR
runtimeverification/rv-nix-tools#14. This change is done to make
`nixpkgs` properly updatable by CI.

In addition, this pull requests adapts the `update-deps.yml` workflow to
also update `rv-nix-tools` that is used to implicitly specify the
revision of `nixpkgs`.

---

###### Review checklist

The author performs the actions on the checklist. The reviewer evaluates
the work and checks the boxes as they are completed.

- [x] **Summary.** Write a summary of the changes. Explain what you did
to fix the issue, and why you did it. Present the changes in a logical
order. Instead of writing a summary in the pull request, you may push a
clean Git history.
- [ ] **Documentation.** Write documentation for new functions. Update
documentation for functions that changed, or complete documentation
where it is missing.
- [ ] **Tests.** Write unit tests for every change. Write the unit tests
that were missing before the changes. Include any examples from the
reported issue as integration tests.
- [ ] **Clean up.** The changes are already clean. Clean up anything
near the changes that you noticed while working. This does not mean only
spatially near the changes, but logically near: any code that interacts
with the changes!

---------

Co-authored-by: Jost Berthold <jost.berthold@gmail.com>

Author: juliankuners

.github/workflows/update-deps.yml

@@ -0,0 +1,44 @@
+name: 'Update Version'
+on:
+  push:
+    branches:
+      - '_update-deps/runtimeverification/rv-nix-tools'
+  workflow_dispatch:
+# Stop in progress workflows on the same branch and same workflow to use latest committed code
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+
+  update-versions:
+    name: 'Update Dependency Versions'
+    runs-on: ubuntu-latest
+    steps:
+      - name: 'Check out code'
+        uses: actions/checkout@v4
+        with:
+          submodules: true
+          token: ${{ secrets.JENKINS_GITHUB_PAT }}
+      - name: 'Configure GitHub user'
+        run: |
+          git config user.name devops
+          git config user.email devops@runtimeverification.com
+      - name: 'Install Nix/Cachix'
+        uses: cachix/install-nix-action@v19
+        with:
+          install_url: https://releases.nixos.org/nix/nix-2.13.3/install
+          extra_nix_config: |
+            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+      - uses: cachix/cachix-action@v12
+        with:
+          name: k-framework
+          authToken: ${{ secrets.CACHIX_PUBLIC_TOKEN }}
+      - name: 'Update nix flake inputs'
+        run: |
+          RV_NIX_TOOLS_VERSION=$(cat deps/rv-nix-tools)
+          sed -i 's!    rv-nix-tools.url = "github:runtimeverification/rv-nix-tools/[a-z0-9\.]*"!    rv-nix-tools.url = "github:runtimeverification/rv-nix-tools/'"${RV_NIX_TOOLS_VERSION}"'"!' flake.nix
+          nix flake update
+          git add flake.nix flake.lock && git commit -m 'flake.{nix,lock}: update Nix derivations' || true
+      - name: 'Push updates'
+        run: git push

deps/rv-nix-tools

@@ -0,0 +1 @@
+854d4f05ea78547d46e807b414faad64cea10ae4

flake.lock

@@ -2,8 +2,9 @@
   description = "K Kore Language Haskell Backend";
 
   inputs = {
-    rv-utils.url = "github:runtimeverification/rv-nix-tools";
-    nixpkgs.follows = "rv-utils/nixpkgs";
+    rv-nix-tools.url = "github:runtimeverification/rv-nix-tools/854d4f05ea78547d46e807b414faad64cea10ae4";
+    nixpkgs.follows = "rv-nix-tools/nixpkgs";
+
     z3 = {
       url = "github:Z3Prover/z3/z3-4.13.4";
       flake = false;
@@ -15,7 +16,7 @@
     };
   };
 
-  outputs = { self, rv-utils, nixpkgs, z3, flake-utils, some-cabal-hashes-lib }:
+  outputs = { self, rv-nix-tools, nixpkgs, z3, flake-utils, some-cabal-hashes-lib }:
   let
     z3Overlay = final: prev: {
       z3 = prev.z3.overrideAttrs (_: {