Bump actions/cache from 4 to 5

Bumps [actions/cache](https://github.com/actions/cache) from 4 to 5.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](https://github.com/actions/cache/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/ci.yml

@@ -56,7 +56,7 @@ jobs:
       - uses: actions/checkout@v5
 
       - name: Cache SpacemanDMM
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ~/SpacemanDMM
           key: ${{ runner.os }}-dreamchecker-${{ hashFiles('dependencies.sh')}}
@@ -90,7 +90,7 @@ jobs:
           chmod -R +x ./tools/ci
 
       - name: Setup Cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: $HOME/BYOND
           key: ${{ runner.os }}-byond