Use nightly Hermes by default when building iOS in OSS (#54864)

Summary:

Changelog: [Internal]

Changes the default behavior for local iOS builds inside the monorepo to use the nightly hermes version (if set) instead of building from source.

If build from source is needed, it's possible to force by using `RCT_BUILD_HERMES_FROM_SOURCE` env variable.

Reviewed By: cipolleschi

Differential Revision: D89042837

Author: j-piasecki

packages/react-native/sdks/hermes-engine/hermes-engine.podspec

@@ -28,6 +28,14 @@ else
   version = versionProperties['HERMES_VERSION_NAME']
 end
 
+# Local monorepo build
+if package['version'] == "1000.0.0" then
+  hermesCompilerVersion = package['dependencies']['hermes-compiler']
+  if hermesCompilerVersion != "0.0.0" then
+    version = hermesCompilerVersion
+  end
+end
+
 source_type = hermes_source_type(version, react_native_path)
 source = podspec_source(source_type, version, react_native_path)