Bump Swatinem/rust-cache from 2.0.1 to 2.1.0 (#1816)

Bumps [Swatinem/rust-cache](https://github.com/Swatinem/rust-cache) from 2.0.1 to 2.1.0.
- [Release notes](https://github.com/Swatinem/rust-cache/releases)
- [Changelog](https://github.com/Swatinem/rust-cache/blob/master/CHANGELOG.md)
- [Commits](Swatinem/rust-cache@22c9328...b894d59)

---
updated-dependencies:
- dependency-name: Swatinem/rust-cache
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/docs.yml

@@ -23,7 +23,7 @@ jobs:
         run:  rustup show
 
       - name: Rust cache
-        uses: Swatinem/rust-cache@22c9328bcba27aa81a32b1bef27c7e3c78052531 # v2.0.1
+        uses: Swatinem/rust-cache@b894d59a8d236e2979b247b80dac8d053ab340dd # v2.1.0
 
       - name: Build rustdocs
         run:  SKIP_WASM_BUILD=1 cargo doc --all --no-deps