MAINT: Bump actions/cache from 5 to 6 (#2074)

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/build_and_test.yml

@@ -44,7 +44,7 @@ jobs:
           python-version: ${{ env.PRE_COMMIT_PYTHON_VERSION }}
 
       - name: Cache pre-commit environments
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/.cache/pre-commit
           key: pre-commit-${{ runner.os }}-${{ hashFiles('.pre-commit-config.yaml') }}

.github/workflows/docs.yml

@@ -113,7 +113,7 @@ jobs:
         # miss -> we do a fresh build and actions/cache saves the result on
         # job success, so the next run with the same SHA hits.
         id: cache
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: doc/_build/html
           key: docs-${{ env.CACHE_VERSION }}-${{ matrix.slug }}-${{ steps.sha.outputs.sha }}