fixup! Add CI job that checks minimal version

Author: gregoire-mullvad

.github/workflows/ci.yml

@@ -67,4 +67,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly
-      - run: cargo build --verbose -Z minimal-versions
+      - uses: dtolnay/rust-toolchain@stable
+      - run: cargo +nightly update --verbose -Z minimal-versions
+      - run: cargo +stable build --locked