To deploy only on new release tags, which follow a semantic versioning pattern (e.g., v1.2.3), you should use a tag filter with a regular expression matching semantic versions.
From the official documentation:
"You can configure Cloud Build to start a build automatically whenever there is a new tag in your source repository by using tag triggers."
- Cloud Build Triggers
Using a tag pattern like \d+\.\d+\.\d* ensures that builds only trigger on properly versioned release tags (minimizing unnecessary executions). This matches standard semver tags such as 1.0.0, 2.1.3, etc.