fix(release): remove unnecessary number from release return type (#34481)

## Current Behavior

The `release` function returned by `createAPI` has a return type of
`Promise<NxReleaseVersionResult | number>`. The `| number` union member
is inaccurate since the function always returns
`NxReleaseVersionResult`, which can mislead consumers of the
programmatic API.

## Expected Behavior

The return type is narrowed to `Promise<NxReleaseVersionResult>`,
accurately reflecting what the function actually returns and giving API
consumers correct type information.

Co-authored-by: Andreas Hörnicke <andreas.hoernicke@contentful.com>

Author: llwt

packages/nx/src/command-line/release/release.ts

@@ -60,7 +60,7 @@ export function createAPI(
 
   return async function release(
     args: ReleaseOptions
-  ): Promise<NxReleaseVersionResult | number> {
+  ): Promise<NxReleaseVersionResult> {
     const projectGraph = await createProjectGraphAsync({ exitOnError: true });
     const overriddenConfig = overrideReleaseConfig ?? {};
     const userProvidedReleaseConfig = ignoreNxJsonConfig