Remove unused cleanup workflow and set artifact retention (#1257)

Signed-off-by: Ludvig Liljenberg <4257730+ludfjig@users.noreply.github.com>

Author: ludfjig

.github/workflows/Benchmarks.yml

@@ -66,3 +66,4 @@ jobs:
           name: benchmarks_${{runner.os}}_${{matrix.hypervisor}}_${{ matrix.cpu }}
           path: ./target/criterion/
           if-no-files-found: error
+          retention-days: 5

.github/workflows/CleanUpReleasesAndPackages.yml

@@ -56,3 +56,4 @@ jobs:
         with:
           name: fuzz-crash-artifacts
           path: fuzz/artifacts/
+          retention-days: 28