feature: fallback to pre-release when no stable version is found (#414)

This allows to specify version like `3.11` or `pypy3.10` in workflows before those versions are released.
This lessen the burden for users of `setup-python` by not having to modify their workflow twice: once when a pre-release is available (e.g. `3.11-dev`) and once when the first stable release is published (e.g. `3.11`)

src/find-pypy.ts

@@ -23,7 +23,8 @@ export async function findPyPyVersion(
   versionSpec: string,
   architecture: string,
   updateEnvironment: boolean,
-  checkLatest: boolean
+  checkLatest: boolean,
+  allowPreReleases: boolean
 ): Promise<{resolvedPyPyVersion: string; resolvedPythonVersion: string}> {
   let resolvedPyPyVersion = '';
   let resolvedPythonVersion = '';
@@ -39,7 +40,8 @@ export async function findPyPyVersion(
         releases,
         pypyVersionSpec.pythonVersion,
         pypyVersionSpec.pypyVersion,
-        architecture
+        architecture,
+        false
       );
 
       if (releaseData) {
@@ -71,6 +73,7 @@ export async function findPyPyVersion(
       pypyVersionSpec.pypyVersion,
       pypyVersionSpec.pythonVersion,
       architecture,
+      allowPreReleases,
       releases
     ));
   }