Bump actions/cache from 4.2.0 to 4.3.0 in /reuse

Bumps [actions/cache](https://github.com/actions/cache) from 4.2.0 to 4.3.0.
- [Release notes](https://github.com/actions/cache/releases)
- [Changelog](https://github.com/actions/cache/blob/main/RELEASES.md)
- [Commits](actions/cache@v4.2.0...v4.3.0)

---
updated-dependencies:
- dependency-name: actions/cache
  dependency-version: 4.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

reuse/action.yml

@@ -43,7 +43,7 @@ runs:
     shell: bash
 
   - name: Restore Cache
-    uses: actions/cache/restore@v4.2.0
+    uses: actions/cache/restore@v4.3.0
     id: cache-venv
     with:
       path: reuse-tool-venv
@@ -73,7 +73,7 @@ runs:
     shell: bash
 
   - name: Save Cache
-    uses: actions/cache/save@v4.2.0
+    uses: actions/cache/save@v4.3.0
     with:
       path: reuse-tool-venv
       key: ${{ steps.cache-venv.outputs.cache-primary-key }}