Fix potential leaks in checker (#36491)

Author: rbuckton

scripts/configurePrerelease.ts

@@ -60,7 +60,7 @@ function updateTsFile(tsFilePath: string, tsFileContents: string, majorMinor: st
     const parsedMajorMinor = majorMinorMatch![1];
     assert(parsedMajorMinor === majorMinor, `versionMajorMinor does not match. ${tsFilePath}: '${parsedMajorMinor}'; package.json: '${majorMinor}'`);
 
-    const versionRgx = /export const version = `\$\{versionMajorMinor\}\.(\d)(-dev)?`;/;
+    const versionRgx = /export const version = `\$\{versionMajorMinor\}\.(\d)(-\w+)?`;/;
     const patchMatch = versionRgx.exec(tsFileContents);
     assert(patchMatch !== null, `The file '${tsFilePath}' seems to no longer have a string matching '${versionRgx.toString()}'.`);
     const parsedPatch = patchMatch![1];