FileLogger API improvement

To ensure the scripts/publish works as intended.

Github: Checkout `main` branch instead of ref on publish job

Avoids potential clashes in apps integrating the library

Use more unique (internal) content provider authorities.

See https://docs.gradle.org/8.8/release-notes.html

Gradle: Update wrapper to version 8.8

Not worth mentioning in CHANGELOG.md as this doesn't affect library
users.

Including matching kotlinx-io version 0.4.0 and kotlin-wrappers version
pre.757. Adjust expect class declarations due to [stricter rules][0] for
abstract members with the K2 compiler. See open [YouTrack issue][1].

[0]: https://kotlinlang.org/docs/k2-compiler-migration-guide.html#stricter-rules-for-abstract-members-in-expected-classes
[1]: https://youtrack.jetbrains.com/issue/KT-59739/K2-MPP-reports-ABSTRACTMEMBERNOTIMPLEMENTED-for-inheritor-in-common-code-when-the-implementation-is-located-in-the-actual

Kotlin: Update to version 2.0.0

Avoid leaking all other used dependencies to Google servers and speed
up dependency resolution.

Gradle: Only query google repository for Android dependencies

Signed-off-by: Sascha Peilicke <[email protected]>