context: remove provenanceBuilderID func

[crazy-max]

This function is not used anymore and has been replaced by

actions-toolkit/src/github.ts

Lines 93 to 95 in 9881e80

	public static workflowRunURL(setAttempts?: boolean): string {
	return `${GitHub.serverURL}/${GitHub.repository}/actions/runs/${GitHub.runId}${setAttempts ? `/attempts/${GitHub.runAttempt}` : ''}`;
	}

Used when solving provenance attributes:

actions-toolkit/src/buildx/build.ts

Line 162 in 9881e80

return core.getBooleanInput(name) ? `builder-id=${GitHub.workflowRunURL(true)}` : 'false';