Bump julia-actions/cache from 2 to 3

Bumps [julia-actions/cache](https://github.com/julia-actions/cache) from 2 to 3.
- [Release notes](https://github.com/julia-actions/cache/releases)
- [Commits](julia-actions/cache@v2...v3)

---
updated-dependencies:
- dependency-name: julia-actions/cache
  dependency-version: '3'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -21,7 +21,7 @@ jobs:
       uses: julia-actions/setup-julia@v2  
 
     - name: Cache Julia packages  
-      uses: julia-actions/cache@v2  
+      uses: julia-actions/cache@v3  
 
     - name: Install dependencies  
       run: | 

.github/workflows/docs.yml

@@ -18,7 +18,7 @@ jobs:
         with:
           version: '1'
 
-      - uses: julia-actions/cache@v2
+      - uses: julia-actions/cache@v3
 
       - name: Install dependencies
         run: julia --project=docs -e '