ci: Update ci.yaml to introduce Java 21 unit testing (#1907) (#1489)

Source-Link: googleapis/synthtool@c06d605
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-java:latest@sha256:6f431774e11cc46619cf093fd1481193c4024031073697fa18f0099b943aab88

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: gcf-owl-bot[bot]

.github/.OwlBot.lock.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-java:latest
-  digest: sha256:bc2bf47c7370f1b1a8a46b0c104ce7e43644ac58902c9de265fe1f253fcc2506
-# created: 2023-10-31T13:44:21.909247346Z
+  digest: sha256:6f431774e11cc46619cf093fd1481193c4024031073697fa18f0099b943aab88
+# created: 2023-12-01T19:50:20.444857406Z

.github/workflows/ci.yaml

@@ -25,7 +25,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
     steps:
     - uses: actions/checkout@v3
     - uses: actions/setup-java@v3

README.md

@@ -59,13 +59,13 @@ implementation 'com.google.cloud:google-cloud-logging'
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-logging:3.15.13'
+implementation 'com.google.cloud:google-cloud-logging:3.15.14'
 ```
 
 If you are using SBT, add this to your dependencies:
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-logging" % "3.15.13"
+libraryDependencies += "com.google.cloud" % "google-cloud-logging" % "3.15.14"
 ```
 <!-- {x-version-update-end} -->
 
@@ -452,7 +452,7 @@ Java is a registered trademark of Oracle and/or its affiliates.
 [kokoro-badge-link-5]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-logging/java11.html
 [stability-image]: https://img.shields.io/badge/stability-stable-green
 [maven-version-image]: https://img.shields.io/maven-central/v/com.google.cloud/google-cloud-logging.svg
-[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-logging/3.15.13
+[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-logging/3.15.14
 [authentication]: https://github.com/googleapis/google-cloud-java#authentication
 [auth-scopes]: https://developers.google.com/identity/protocols/oauth2/scopes
 [predefined-iam-roles]: https://cloud.google.com/iam/docs/understanding-roles#predefined_roles