CI: fix compile_commands.json caching (xapi-project#6356)

When the cache for compile_commands.json got reused we didn't install
the OCaml compiler, which caused failures in the static analyzer,
because it couldn't locate the compiler runtime headers.

Do not skip setup-xapi-environment when the cache is reused.

This could be optimized to skip installing dune packages (install just
the compiler), but for now just install everything to avoid the error.

Now when the cache is used we only skip installing/running
dune-compiledb.

Author: edwintorok

.github/workflows/codechecker.yml

@@ -27,39 +27,22 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Restore cache for compile_commands.json
-        uses: actions/cache/restore@v4
-        id: cache-cmds
-        with:
-          path: compile_commands.json
-          key: compile_commands.json-v1-${{ hashFiles('**/dune') }}
-
       - name: Setup XenAPI environment
-        if: steps.cache-cmds.outputs.cache-hit != 'true'
         uses: ./.github/workflows/setup-xapi-environment
         with:
           xapi_version: ${{ env.XAPI_VERSION }}
 
       - name: Install dune-compiledb to generate compile_commands.json
-        if: steps.cache-cmds.outputs.cache-hit != 'true'
         run: |
           opam pin add -y ezjsonm https://github.com/mirage/ezjsonm/releases/download/v1.3.0/ezjsonm-1.3.0.tbz
           opam pin add -y dune-compiledb https://github.com/edwintorok/dune-compiledb/releases/download/0.6.0/dune-compiledb-0.6.0.tbz
 
       - name: Trim dune cache
-        if: steps.cache-cmds.outputs.cache-hit != 'true'
         run: opam exec -- dune cache trim --size=2GiB         
 
       - name: Generate compile_commands.json
-        if: steps.cache-cmds.outputs.cache-hit != 'true'
         run: opam exec -- make compile_commands.json
 
-      - name: Save cache for cmds.json
-        uses: actions/cache/save@v4
-        with:
-          path: compile_commands.json
-          key: ${{ steps.cache-cmds.outputs.cache-primary-key }}
-
       - name: Upload compile commands json
         uses: actions/upload-artifact@v4
         with: