ci: use local action to make make cache keys consistent (#20538)

The advantages of using an action is that it reduces boilerplate and
repetition from the main ci.yml workflow.

.github/actions/cache/action.yml

@@ -0,0 +1,22 @@
+name: 'Cache'
+description: "This action caches neovim dependencies"
+runs:
+  using: "composite"
+  steps:
+    - run: echo "CACHE_KEY=${{ github.job }}-${{ github.base_ref }}" >> $GITHUB_ENV
+      shell: bash
+
+    - if: ${{ matrix }}
+      run: echo "CACHE_KEY=$CACHE_KEY-${{ join(matrix.*, '-') }}" >> $GITHUB_ENV
+      shell: bash
+
+    # Avoid using '**/CMakeLists.txt' (or any pattern starting with '**/') even
+    # if it makes the expression below simpler. hashFiles() has a timer that
+    # will fail the job if it times out, which can happen if there are too many
+    # files to search through.
+    - uses: actions/cache@v3
+      with:
+        path: ${{ env.CACHE_NVIM_DEPS_DIR }}
+        key: ${{ env.CACHE_KEY }}-${{ hashFiles('cmake**', 'ci/**',
+          '.github/workflows/ci.yml', 'CMakeLists.txt',
+          'runtime/CMakeLists.txt', 'src/nvim/**/CMakeLists.txt') }}

.github/workflows/ci.yml

@@ -69,12 +69,7 @@ jobs:
           mkdir -p $HOME/.cache
           cp $build_dir/uncrustify ${{ env.CACHE_UNCRUSTIFY }}
 
-      - name: Cache artifacts
-        uses: actions/cache@v3
-        with:
-          path: |
-            ${{ env.CACHE_NVIM_DEPS_DIR }}
-          key: lint-${{ hashFiles('cmake/*', '**/CMakeLists.txt', '!cmake.deps/**CMakeLists.txt') }}-${{ github.base_ref }}
+      - uses: ./.github/actions/cache
 
       - name: Build third-party deps
         run: ./ci/before_script.sh
@@ -167,12 +162,7 @@ jobs:
             ninja-build \
             pkg-config
 
-      - name: Cache artifacts
-        uses: actions/cache@v3
-        with:
-          path: |
-            ${{ env.CACHE_NVIM_DEPS_DIR }}
-          key: lint-${{ hashFiles('cmake/*', '**/CMakeLists.txt', '!cmake.deps/**CMakeLists.txt') }}-${{ github.base_ref }}
+      - uses: ./.github/actions/cache
 
       - name: Build third-party deps
         run: ./ci/before_script.sh
@@ -273,12 +263,7 @@ jobs:
       - name: Setup interpreter packages
         run: ./ci/install.sh
 
-      - name: Cache dependencies
-        uses: actions/cache@v3
-        with:
-          path: |
-            ${{ env.CACHE_NVIM_DEPS_DIR }}
-          key: ${{ matrix.runner }}-${{ matrix.flavor }}-${{ matrix.cc }}-${{ hashFiles('cmake/*', 'cmake.deps/**', '**/CMakeLists.txt') }}-${{ github.base_ref }}
+      - uses: ./.github/actions/cache
 
       - name: Build third-party deps
         run: ./ci/before_script.sh
@@ -315,15 +300,13 @@ jobs:
     timeout-minutes: 45
     env:
       DEPS_BUILD_DIR: ${{ github.workspace }}/nvim-deps
+      CACHE_NVIM_DEPS_DIR: ${{ github.workspace }}/nvim-deps
       DEPS_PREFIX: ${{ github.workspace }}/nvim-deps/usr
     name: windows (MSVC_64)
     steps:
       - uses: actions/checkout@v3
 
-      - uses: actions/cache@v3
-        with:
-          path: ${{ env.DEPS_BUILD_DIR }}
-          key: windows-${{ hashFiles('cmake.deps/**') }}
+      - uses: ./.github/actions/cache
 
       - name: Set env
         run: ./.github/workflows/env.ps1