Bump actions/cache (#31)

Bumps [actions/cache](https://github.com/actions/cache) from 26968a09c0ea4f3e233fdddbafd1166051a095f6 to 2.1.5. This release includes the previously tagged commit.
- [Release notes](https://github.com/actions/cache/releases)
- [Commits](actions/cache@26968a0...1a9e213)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -36,7 +36,7 @@ jobs:
         pubspec-file-path: code/pubspec.yaml
     - name: Cache Flutter
       id: flutter-cache
-      uses: actions/cache@26968a09c0ea4f3e233fdddbafd1166051a095f6
+      uses: actions/cache@1a9e2138d905efd099035b49d8b7a3888c653ca8
       with:
         path: flutter
         key: ${{ env.cache-name }}-ubuntu-latest-${{ steps.get-flutter-version.outputs.version }}-${{ hashFiles('code/pubspec.lock') }}

.github/workflows/deployment.yml

@@ -45,7 +45,7 @@ jobs:
         pubspec-file-path: code/pubspec.yaml
     - name: Cache Flutter
       id: flutter-cache
-      uses: actions/cache@26968a09c0ea4f3e233fdddbafd1166051a095f6
+      uses: actions/cache@1a9e2138d905efd099035b49d8b7a3888c653ca8
       with:
         path: flutter
         key: ${{ env.cache-name }}-ubuntu-latest-${{ steps.get-flutter-version.outputs.version }}-${{ hashFiles('code/pubspec.lock') }}
@@ -123,7 +123,7 @@ jobs:
         pubspec-file-path: code/pubspec.yaml
     - name: Cache Flutter
       id: flutter-cache
-      uses: actions/cache@26968a09c0ea4f3e233fdddbafd1166051a095f6
+      uses: actions/cache@1a9e2138d905efd099035b49d8b7a3888c653ca8
       with:
         path: flutter
         key: ${{ env.cache-name }}-${{ matrix.os }}-${{ steps.get-flutter-version.outputs.version }}-${{ hashFiles('code/pubspec.lock') }}