chore: bump actions/cache from 5 to 6 (#890)

Bumps actions/cache from 5 to 6.

https://github.com/actions/cache/releases

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -39,7 +39,7 @@ jobs:
               run: echo "short_sha=$(git rev-parse --short HEAD)" >> "$GITHUB_OUTPUT"
 
             - name: Cache .lake
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                   path: .lake
                   # The SHA is in the key to get the most recent cache possible, rather than just saving a single one for each Lean/deps version and not touching it.
@@ -79,7 +79,7 @@ jobs:
                   cache-dependency-glob: "browser-tests/pyproject.toml"
 
             - name: Cache Playwright browsers
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                   path: .playwright-browsers
                   key: playwright-${{ runner.os }}-${{ hashFiles('browser-tests/uv.lock') }}
@@ -173,7 +173,7 @@ jobs:
 
             # uv and Playwright are installed before `lake test` above.
             - name: Cache literate-config test project
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                   path: test-projects/literate-config/.lake
                   key:
@@ -185,7 +185,7 @@ jobs:
                       literate-config-${{ runner.os }}-${{ hashFiles('test-projects/literate-config/lean-toolchain') }}-${{ hashFiles('test-projects/literate-config/lake-manifest.json') }}-
 
             - name: Cache literate-multi-root test project
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                   path: test-projects/literate-multi-root/.lake
                   key:

.github/workflows/release-tag.yml

@@ -31,7 +31,7 @@ jobs:
               run: echo "short_sha=$(git rev-parse --short HEAD)" >> "$GITHUB_OUTPUT"
 
             - name: Cache .lake
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                   path: .lake
                   key:

.github/workflows/update-subverso.yml

@@ -71,7 +71,7 @@ jobs:
 
             - name: Cache Playwright browsers
               if: steps.check-changes.outputs.changed == 'true'
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                   path: .playwright-browsers
                   key: playwright-${{ runner.os }}-${{ hashFiles('browser-tests/uv.lock') }}