Split release workflow so preflight-spec publishes independently

preflight-spec has no Orbital dependencies and must be published before
Orbital can build, so run it as a separate step that won't fail when
Orbital snapshots are unavailable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: martypitt

.github/workflows/release.yml

@@ -30,8 +30,11 @@ jobs:
         GPG_PASSPHRASE: ${{ secrets.GPG_PASSPHRASE }}
       run: echo "GPG key loaded"
 
-    - name: Build and publish
-      run: ./gradlew build :preflight-spec:publishMavenPublicationToOrbitalRepository :preflight-core:preflight-gradle-plugin:publishPlugins :preflight-core:preflight-runtime:publishMavenPublicationToOrbitalRepository
+    - name: Publish preflight-spec
+      run: cd preflight-spec && ./gradlew build publishMavenPublicationToOrbitalRepository
+
+    - name: Build and publish preflight-core
+      run: ./gradlew build :preflight-core:preflight-gradle-plugin:publishPlugins :preflight-core:preflight-runtime:publishMavenPublicationToOrbitalRepository
       env:
         GRADLE_PUBLISH_KEY: ${{ secrets.GRADLE_PUBLISH_KEY }}
         GRADLE_PUBLISH_SECRET: ${{ secrets.GRADLE_PUBLISH_SECRET }}