chore: Java 8 unit test to build code in Java 17 and run tests on Java 8 (#1800) (#2508)

* Our Java projects are configured to produce Java 8-compatible bytecode via https://github.com/googleapis/java-shared-config/blob/main/pom.xml#L848. This unit test change ensures this config is applied correctly.

* This change also switches the JDK distribution of GitHub Actions to temurin from zulu.

* For the repositories that mark "dependencies (8)" and "dependencies (11)" as required, they should point to only "dependencies (17)" via `.github/sync-repo-settings.yaml` and repo's Settings tab.
Source-Link: googleapis/synthtool@cbe0100
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-java:latest@sha256:32851debfefed2b66038e0141f1b5c2103bb59ba80b7475adbc10ef7abab3de7

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:af2eda87a54601ae7b7b2be5055c17b43ac98a7805b586772db314de8a7d4a1d
-# created: 2023-06-16T02:10:09.149325782Z
+  digest: sha256:32851debfefed2b66038e0141f1b5c2103bb59ba80b7475adbc10ef7abab3de7
+# created: 2023-06-22T15:06:52.039318836Z

.github/dependabot.yml

@@ -6,12 +6,14 @@ updates:
       interval: "daily"
     # Disable version updates for Maven dependencies
     # we use renovate-bot as well as shared-dependencies BOM to update maven dependencies.
-    ignore: "*"
+    ignore:
+      - dependency-name: "*"
   - package-ecosystem: "pip"
     directory: "/"
     schedule:
       interval: "daily"
     # Disable version updates for pip dependencies
     # If a security vulnerability comes in, we will be notified about 
     # it via template in the synthtool repository.
-    ignore: "*"
+    ignore:
+      - dependency-name: "*"