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](actions/cache@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>

Author: dependabot[bot]

.github/workflows/rust.yml

@@ -88,7 +88,7 @@ jobs:
         id: msrv-toolchain
         if: matrix.rust.name == 'MSRV'
       # on non-msrv runs, use one cache key ...
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/git
@@ -97,7 +97,7 @@ jobs:
           key: "${{runner.os}} Rust ${{steps.rust-toolchain.outputs.cachekey}}"
         if: matrix.rust.name != 'MSRV'
       # ... and on msrv runs, use another
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/git
@@ -157,7 +157,7 @@ jobs:
         with:
           toolchain: ${{matrix.rust.toolchain}}
         id: rust-toolchain
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/git
@@ -200,7 +200,7 @@ jobs:
       - name: Get Tarpaulin Version
         id: tarpaulin-version
         run: echo "version=$(wget -qO- 'https://crates.io/api/v1/crates/cargo-tarpaulin' | jq -r '.crate.max_stable_version')" >>$GITHUB_OUTPUT
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/bin/cargo-tarpaulin