Bump coursier/cache-action from 5 to 6

Bumps [coursier/cache-action](https://github.com/coursier/cache-action) from 5 to 6.
- [Release notes](https://github.com/coursier/cache-action/releases)
- [Commits](coursier/cache-action@v5...v6)

---
updated-dependencies:
- dependency-name: coursier/cache-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v2
-      - uses: coursier/cache-action@v5
+      - uses: coursier/cache-action@v6
       - uses: actions/setup-java@v4
         with:
           java-version: "11"

.github/workflows/ghpages.yml

@@ -17,7 +17,7 @@ jobs:
         with:
           java-version: "11"
           distribution: "adopt"
-      - uses: coursier/cache-action@v5
+      - uses: coursier/cache-action@v6
       - name: Build
         run: sbt manual/makeSite
       - name: Deploy

.github/workflows/release.yml

@@ -16,7 +16,7 @@ jobs:
           java-version: "8"
           distribution: "adopt"
       - uses: olafurpg/setup-gpg@v3
-      - uses: coursier/cache-action@v5
+      - uses: coursier/cache-action@v6
       - name: Publish
         run: sbt clean ci-release
         env: