delete background executor

[sammy-SC]

Summary: changelog: [internal]

Reviewed By: fkgozali

Differential Revision: D58737295

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D58737295

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	21,234,707	-65,697
android	hermes	armeabi-v7a	n/a	--
android	hermes	x86	n/a	--
android	hermes	x86_64	n/a	--
android	jsc	arm64-v8a	24,431,912	-65,579
android	jsc	armeabi-v7a	n/a	--
android	jsc	x86	n/a	--
android	jsc	x86_64	n/a	--

Base commit: b4b6614
Branch: main

[facebook-github-bot]

This pull request was exported from Phabricator. Differential Revision: D58737295

[facebook-github-bot]

This pull request has been merged in 8f98c58.

[github-actions]

This pull request was successfully merged by @sammy-SC in 8f98c58.

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