ci: mark beta releases as Latest

GitHub will not let a prerelease be Latest ("Drafts and prereleases cannot be
set as latest"), and the prerelease flag is not separable from the -beta
version: release-please derives it from the version itself. So clear the flag
after publishing instead. The condition takes itself out of service once 2.0.0
ships, since a stable release becomes Latest on its own.

beep boop

Author: khvn26

.github/workflows/release.yml

@@ -32,3 +32,10 @@ jobs:
       - uses: actions/attest@508db95dd578ae2727ebd6217d5ba78e4fbda05d # v4.2.1
         with:
           subject-checksums: ./dist/checksums.txt
+
+      # During public beta the newest beta is what people
+      # should land on, so clear it.
+      - if: contains(github.ref_name, '-beta')
+        run: gh release edit "$GITHUB_REF_NAME" --prerelease=false --latest
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}