Run the AUR package's check() in the AUR build job

makepkg runs the PKGBUILD's check() (cargo test --frozen --lib) for every
AUR install, and the build job skipped it with --nocheck on the claim that
ci.yml already covered the tests. ci.yml runs the library tests, but not the
way an AUR install does: frozen and offline against the dependencies
prepare() fetched, with the Arch toolchain, inside the Arch container. A
test that fails only there would first be seen by users installing the
package. Drop --nocheck so the build job runs check() the same way.

.github/workflows/aur-publish.yml

@@ -138,9 +138,11 @@ jobs:
             bash namcap-gate.sh PKGBUILD
             echo "::endgroup::"
             echo "::group::makepkg build"
-            # --nocheck: skip the PKGBUILD check() (cargo test --lib); the test
-            # suite is already covered by ci.yml. This job validates packaging.
-            makepkg -s --noconfirm --nocheck
+            # No --nocheck. makepkg runs check() by default, so every AUR user
+            # runs it and this job must too. ci.yml runs the tests, but not this
+            # way: frozen and offline against what prepare fetched, with the
+            # Arch toolchain, in this container.
+            makepkg -s --noconfirm
             echo "::endgroup::"
             echo "::group::namcap built package"
             bash namcap-gate.sh ./*.pkg.tar.*