tests: Correct heading in static checks test

The github static checks action has a section heading called "Building
rust".  It doesn't actually build rust, though, just installs it with
rustup.  Correct the misleading message.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

.github/workflows/static-checks.yaml

@@ -60,7 +60,7 @@ jobs:
         cd ${GOPATH}/src/github.com/${{ github.repository }} && ./ci/setup.sh
       env:
         GOPATH: ${{ runner.workspace }}/kata-containers
-    - name: Building rust
+    - name: Installing rust
       if: ${{ !contains(github.event.pull_request.labels.*.name, 'force-skip-ci') }}
       run: |
         cd ${GOPATH}/src/github.com/${{ github.repository }} && ./ci/install_rust.sh