CI: update rust

Author: DarthGandalf

.github/workflows/run-tests.yml

@@ -24,7 +24,9 @@ jobs:
       - name: Install deps
         run: |
           apt update
-          apt install -y libgtk-4-dev cargo rust-clippy meson gettext blueprint-compiler desktop-file-utils
+          apt install -y libgtk-4-dev rustup meson gettext blueprint-compiler desktop-file-utils
+
+      - run: rustup update stable && rustup default stable
 
       - name: Run sccache-cache
         uses: mozilla-actions/[email protected]