fix(versioning/ruby): prevent extra vv prefix addition (#35667)

Author: RahulGautamSingh

lib/modules/versioning/ruby/index.spec.ts

@@ -253,6 +253,7 @@ describe('modules/versioning/ruby/index', () => {
   it.each`
     currentValue             | rangeStrategy        | currentVersion | newVersion   | expected
     ${'1.0.3'}               | ${'pin'}             | ${'1.0.3'}     | ${'1.2.3'}   | ${'1.2.3'}
+    ${'v1.0.3'}              | ${'auto'}            | ${'v1.0.3'}    | ${'v1.2.3'}  | ${'v1.2.3'}
     ${'v1.0.3'}              | ${'pin'}             | ${'1.0.3'}     | ${'1.2.3'}   | ${'v1.2.3'}
     ${'= 1.0.3'}             | ${'pin'}             | ${'1.0.3'}     | ${'1.2.3'}   | ${'= 1.2.3'}
     ${'!= 1.0.3'}            | ${'pin'}             | ${'1.0.4'}     | ${'1.2.3'}   | ${'1.2.3'}

lib/modules/versioning/ruby/index.ts

@@ -103,7 +103,10 @@ const getNewValue = ({
 }: NewValueConfig): string | null => {
   let newValue = null;
   if (isVersion(currentValue)) {
-    newValue = currentValue.startsWith('v') ? 'v' + newVersion : newVersion;
+    newValue =
+      currentValue.startsWith('v') && !newVersion.startsWith('v')
+        ? `v${newVersion}`
+        : newVersion;
   } else if (currentValue.replace(regEx(/^=\s*/), '') === currentVersion) {
     newValue = currentValue.replace(currentVersion, newVersion);
   } else {