CDK version use the SemVer format (#63740)

This PR is making the CDK to use SemVer.

It requires the contributor to manually set the CDK version allowing to define patch/minor/major version.

This is a first step into improving the way we manage the CDK versioning.

The changes are the following ones:

java-bulk-cdk-publish.yml: remove the autogeneration of the version. Add a check step to ensure that we don't override the latest version
java-cdk-tests.yml: add a step in the CDK CI to ensure that the we don't override existing version.
README.md: Update the doc
build.gradle: remove the task which generate the build number; add a task to check the version doesn't conflict with the latest version.


Co-authored-by: Davin Chia <davinchia@gmail.com>

.github/workflows/java-cdk-tests.yml

@@ -58,6 +58,16 @@ jobs:
         with:
           distribution: "zulu"
           java-version: "21"
+      # Help CDK Devs understand CDK version should be incremented on changes.
+      - name: Error if CDK Version Exists
+        uses: burrunan/gradle-cache-action@v1
+        env:
+          CI: true
+        with:
+          job-id: bulk-cdk-publish
+          concurrent: true
+          gradle-distribution-sha-256-sum-warning: false
+          arguments: --scan :airbyte-cdk:bulk:checkBuildNumber
       - name: Run Java CDK Tests
         uses: burrunan/gradle-cache-action@v3
         env: