Bump julia-actions/cache from 2.0.1 to 2.0.4

Bumps [julia-actions/cache](https://github.com/julia-actions/cache) from 2.0.1 to 2.0.4.
- [Release notes](https://github.com/julia-actions/cache/releases)
- [Changelog](https://github.com/julia-actions/cache/blob/main/devdocs/making_a_new_release.md)
- [Commits](julia-actions/cache@580d2b6...8608484)

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

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

.github/workflows/CI.yml

@@ -71,7 +71,7 @@ jobs:
       - uses: julia-actions/setup-julia@780022b48dfc0c2c6b94cfee6a9284850107d037 # v2.3.0
         with:
           version: ${{ matrix.version }}
-      - uses: julia-actions/cache@580d2b69d895343992af2cbad49c32a0149c2cde # v2.0.1
+      - uses: julia-actions/cache@8608484607cba0bdb5437a7bad85d6502499d029 # v2.0.4
 
       - uses: r-lib/actions/setup-r@929c772977a3a13c8733b363bf5a2f685c25dd91 # v2.9.0
         with: