[RN][GHA] Properly export the hermes tarball path to reuse it in RNTester

[cipolleschi]

Summary:

While working on GHA, I realized that RNTester is not reusing the hermes package we create in the previous steps.

This change should fix that, saving ~5 minute per RNTester test as it does not have to rebuild hermes every time.

Changelog:

[Internal] - Improve CI to reuse hermes tarballs

Test Plan:

Before	After

[facebook-github-bot]

@cipolleschi has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	20,364,462	-9
android	hermes	armeabi-v7a	n/a	--
android	hermes	x86	n/a	--
android	hermes	x86_64	n/a	--
android	jsc	arm64-v8a	23,569,578	-11
android	jsc	armeabi-v7a	n/a	--
android	jsc	x86	n/a	--
android	jsc	x86_64	n/a	--

Base commit: 1c6bf24
Branch: main

[facebook-github-bot]

@cipolleschi merged this pull request in c7d3220.

[github-actions]

This pull request was successfully merged by @cipolleschi in c7d3220.

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