Cleanup: Remove unused exports in github-auth.server.ts and session.server.ts

[MoSattler]

Changes

This pull request removes some exports that seem to be unused in the following files:

1. app/utils/github-auth.server.ts
2. app/utils/session.server.ts

Details

app/utils/github-auth.server.ts:

• Removed complete file, as it doesn't appear to be utilized anywhere in the codebase.

app/utils/session.server.ts:

• Removed exports for getSession, destroySession and commitSession.

I've done a search throughout the codebase and couldn't find references to the removed exports. However, I might have missed some usages.