Skip use-hermes-nightly when hermes-compiler is already pinned (#56505)

Summary:
`use-hermes-nightly` unconditionally overwrites the `hermes-compiler` with whatever the `latest-v1` tag currently points to. On release branches, where `hermes-compiler` is pinned to a specific version, it replaces the pin. This doesn't cause an issue until the `latest-v1` tag moves off the pinned version.

Looks to have been introduced by #53837.

bypass-github-export-checks

## Changelog:

[INTERNAL] [FIXED] - Preserve pinned `hermes-compiler` version when running `use-hermes-nightly` on release branches.

Pull Request resolved: #56505

Test Plan: With `hermes-compiler` manually set to a real version, the script returns early without modifying `package.json` or `hermes-engine/version.properties`.

Reviewed By: cortinico

Differential Revision: D101633376

Pulled By: cipolleschi

fbshipit-source-id: 666baa1a7838272b18e326b8597394d66b81343c

Author: alanjhughes

scripts/releases/use-hermes-nightly.js

@@ -10,9 +10,20 @@
 
 'use strict';
 
+const {getReactNativePackage} = require('../shared/monorepoUtils');
 const {updateHermesVersionsToNightly} = require('./utils/hermes-utils');
 
 async function main() {
+  const {packageJson} = await getReactNativePackage();
+  const hermesCompilerVersion = packageJson.dependencies?.['hermes-compiler'];
+
+  if (hermesCompilerVersion != null && hermesCompilerVersion !== '0.0.0') {
+    console.log(
+      `Skipping hermes nightly update: hermes-compiler is pinned to ${hermesCompilerVersion}`,
+    );
+    return;
+  }
+
   await updateHermesVersionsToNightly();
 }