ci: check if crate can be packaged

This way, we can early spot issues before they occur in unfortunate situations,
as happened with [0].

[0] #1338

Author: phip1611

.github/workflows/rust.yml

@@ -121,6 +121,17 @@ jobs:
         # library packages. Note that xtask isn't used or built here; since it's
         # just a dev tool we don't care about the MSRV for that package.
         run: cargo build --target x86_64-unknown-uefi -p uefi-test-runner
+  # Tests that the published crates keep being package-able (thus, releasable).
+  package:
+    name: Package Crates
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+      - uses: Swatinem/rust-cache@v2
+      - name: Build
+        run: cargo package -p uefi -p uefi-raw -p uefi-macros
+
   # This job requires the nightly channel, but keep it as a separate job from
   # `nightly_channel` because it takes a while to run.
   build_feature_permutations: