Remove unnecessary settings.xml and scripts for sonatype publishing.

The settings.xml file is no longer needed since we can set the username and password from the actions/java-setup configs. I'm also inlining the deployment command to align with how we do things in the release.yml workflow to make it easier to share this job in the future.

RELNOTES=N/A
PiperOrigin-RevId: 413765250

.github/workflows/ci.yml

@@ -99,6 +99,9 @@ jobs:
         with:
           distribution: '${{ env.USE_JAVA_DISTRIBUTION }}'
           java-version: '${{ env.USE_JAVA_VERSION }}'
+          server-id: sonatype-nexus-snapshots
+          server-username: CI_DEPLOY_USERNAME
+          server-password: CI_DEPLOY_PASSWORD
       - name: 'Check out repository'
         uses: actions/checkout@v2
       - name: 'Cache local Maven repository'
@@ -132,7 +135,12 @@ jobs:
         env:
           GH_TOKEN: ${{ github.token }}
       - name: 'Publish latest snapshot'
-        run: ./util/publish-snapshot-on-commit.sh
+        run: |
+          util/deploy-all.sh \
+            "deploy:deploy-file" \
+            "HEAD-SNAPSHOT" \
+            "-DrepositoryId=sonatype-nexus-snapshots" \
+            "-Durl=https://oss.sonatype.org/content/repositories/snapshots"
         shell: bash
         env:
           CI_DEPLOY_USERNAME: ${{ secrets.CI_DEPLOY_USERNAME }}