Merge pull request #601 from Concordium/update-cache-version

Update the cache version in github actions.

Author: td202

.github/workflows/build-test-sources.yaml

@@ -173,7 +173,7 @@ jobs:
     # Set up Rust and restore dependencies and targets from cache.
     # This must be done before checking the Rust sources.
     - name: Cache cargo dependencies and targets
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: |
           ~/.cargo/registry
@@ -230,22 +230,22 @@ jobs:
     # but will fall back to cache entries from different versions if no match is found.
     - name: Cache stack global package DB
       id: stack-global
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ~/.stack
         key: ${{ runner.os }}-{{ env.dummy }}-stack-global-${{ matrix.plan.ghc }}-${{ hashFiles('**.yaml') }}
         restore-keys: |
           ${{ runner.os }}-{{ env.dummy }}-stack-global-${{ matrix.plan.ghc }}
     - name: Cache stack-installed programs in '~/.local/bin'
       id: stack-programs
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ~/.local/bin
         key: ${{ runner.os }}-{{ env.dummy }}-stack-programs-${{ matrix.plan.ghc }}-${{ hashFiles('**.yaml') }}
         restore-keys: |
           ${{ runner.os }}-{{ env.dummy }}-stack-programs-${{ matrix.plan.ghc }}
     - name: Cache '.stack-work'
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: .stack-work
         key: ${{ runner.os }}-{{ env.dummy }}-stack-work-${{ matrix.plan.ghc }}-${{ hashFiles('**.yaml') }}