perf(setup-flutter): persist flutter-sdk in /opt/hostedtoolcache on Linux Docker runners and expose dart-sdk on PATH [skip ci]

setup-flutter/action.yml

@@ -25,7 +25,10 @@ runs:
       if: runner.os != 'Windows'
       shell: bash
       run: |
+        LOCK_DIR="/opt/hostedtoolcache/flutter-sdk-setup.lock"
+        if [ ! -d "/opt/hostedtoolcache" ] || [ ! -w "/opt/hostedtoolcache" ]; then
           LOCK_DIR="${TMPDIR:-/tmp}/flutter-sdk-setup.lock"
+        fi
         for i in {1..60}; do
           if mkdir "$LOCK_DIR" 2>/dev/null; then
             break
@@ -35,6 +38,10 @@ runs:
         done
 
         SDK_DIR="$HOME/flutter-sdk"
+        if [ -d "/opt/hostedtoolcache" ] && [ -w "/opt/hostedtoolcache" ]; then
+          SDK_DIR="/opt/hostedtoolcache/flutter-sdk"
+        fi
+
         CLONE_URL="${{ inputs.mirror_url }}"
         if [ -n "${{ inputs.git_token }}" ] && [[ "$CLONE_URL" == https://* ]]; then
           CLONE_URL="https://git:${{ inputs.git_token }}@${CLONE_URL#https://}"
@@ -47,8 +54,10 @@ runs:
             echo "Failed to clone from mirror, falling back to GitHub..."
             git clone https://github.com/flutter/flutter.git "$SDK_DIR"
           }
+          git -C "$SDK_DIR" config --global --add safe.directory "$SDK_DIR" || true
           git -C "$SDK_DIR" checkout "${{ inputs.version }}"
         else
+          git -C "$SDK_DIR" config --global --add safe.directory "$SDK_DIR" || true
           CURRENT_COMMIT=$(git -C "$SDK_DIR" rev-parse HEAD 2>/dev/null || true)
           if [ "$CURRENT_COMMIT" != "${{ inputs.version }}" ] && [ "${{ inputs.version }}" != "master" ]; then
             echo "Checking out Flutter ${{ inputs.version }}..."
@@ -113,8 +122,12 @@ runs:
       shell: bash
       run: |
         SDK_DIR="$HOME/flutter-sdk"
-        export PATH="$SDK_DIR/bin:$PATH"
+        if [ -d "/opt/hostedtoolcache/flutter-sdk" ]; then
+          SDK_DIR="/opt/hostedtoolcache/flutter-sdk"
+        fi
+        export PATH="$SDK_DIR/bin:$SDK_DIR/bin/cache/dart-sdk/bin:$PATH"
         echo "$SDK_DIR/bin" >> $GITHUB_PATH
+        echo "$SDK_DIR/bin/cache/dart-sdk/bin" >> $GITHUB_PATH
 
         if [ "${{ inputs.enable_windowing }}" = "true" ]; then
           "$SDK_DIR/bin/flutter" config --enable-windowing
@@ -127,7 +140,8 @@ runs:
       run: |
         $sdkDir = "C:\flutter-sdk"
         [System.IO.File]::AppendAllText($env:GITHUB_PATH, "$sdkDir\bin`r`n")
-        $env:PATH = "$sdkDir\bin;$env:PATH"
+        [System.IO.File]::AppendAllText($env:GITHUB_PATH, "$sdkDir\bin\cache\dart-sdk\bin`r`n")
+        $env:PATH = "$sdkDir\bin;$sdkDir\bin\cache\dart-sdk\bin;$env:PATH"
 
         if ("${{ inputs.enable_windowing }}" -eq "true") {
           & "$sdkDir\bin\flutter.bat" config --enable-windowing