Refactor J2CL release workflows to prioritize validation and testing.

This change restructures the release process to ensure that all tests and initial validations (branch checks and tag existence) are successfully completed before any release artifacts are created or tags are pushed.

 It also cleans up unused parameters: `continue_if_tag_exists` and `create_github_release`.

PiperOrigin-RevId: 904642344

Author: jDramaix

.github/workflows/release.yaml

@@ -29,11 +29,6 @@ on:
         description: 'The base RC version to use to create the final release. Should be formatted as X.Y.Z-RC.N'
         type: string
         required: false
-      continue_if_tag_exists:
-        description: 'Continue the workflow even if the GitHub tag already exists'
-        type: boolean
-        required: true
-        default: false
 
 jobs:
   validate_inputs:
@@ -102,7 +97,6 @@ jobs:
       version: ${{ github.event.inputs.version }}
       git_ref: ${{ github.event.inputs.base_rc_version && format('refs/tags/{0}', github.event.inputs.base_rc_version) || github.ref }}
       publish_to_sonatype: ${{ github.event.repository.name != 'jsinterop-generator' && github.event.repository.name != 'j2cl' }}
-      continue_if_tag_exists: ${{ github.event.inputs.continue_if_tag_exists == 'true' }}
       publish_to_bcr: ${{ github.event.repository.name != 'jsinterop-annotations' }}
 
     # Allow the reusable workflow to access the secrets.