refactor(core): drop injection context assertion in production

[arturovt]

In other parts of the code, calls to the assertInInjectionContext function are guarded with ngDevMode. This change aligns these parts of the code with other implementations that drop such assertions in production.

[thePunderWoman]

LGTM

[ngbot]

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[thePunderWoman]

This PR was merged into the repository by commit 9416483.

The changes were merged into the following branches: main, 20.0.x

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