Determine the next build number to use based on a given format. If we have both dev and beta pre-releases, we want the version build numbers to increment independently from one another rather than be based on a global run number. This is accomplished with a regex format parameter.

Required Provide a regular expression to match other git tags with the same incrementing build number. Capture the build number.

Example: 1.0.0-beta(\d+)

See this action's own distribute.yml action to see how we set the format based on the package.json version and current pre-release branch.

The next build number.