Bug: app auth cache keys missing app_id

[zegl]

This makes the cache multi-app aware, and so that it can handle JWT tokens from multiple apps

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 22.22222% with 7 lines in your changes are missing coverage. Please review.

Project coverage is 35.21%. Comparing base (57ead1b) to head (55c22ba).

Files	Patch %	Lines
githubkit/auth/app.py	22.22%	7 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #95 +/- ## ========================================== - Coverage 35.21% 35.21% -0.01% ========================================== Files 2430 2430 Lines 124901 124905 +4 ========================================== + Hits 43986 43987 +1 - Misses 80915 80918 +3 ``` | [Flag](https://app.codecov.io/gh/yanyongyu/githubkit/pull/95/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Ju4tCode) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/yanyongyu/githubkit/pull/95/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Ju4tCode) | `35.21% <22.22%> (-0.01%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Ju4tCode#carryforward-flags-in-the-pull-request-comment) to find out more.

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[zegl]

It seems the installation cache key also missing the app id.

Yeah, but I don't think it's as critical, as different installation IDs imply different app IDs.