Fix `uninlined_format_args` in server codegen

[ysaito1001]

Bumping MSRV to 1.88.0 required us to fix uninlined_format_args throughout the codebase, e.g.
Fix from:

format!("{}", abc);

To:

format!("{abc}");

The server codegen encountered the warning in the following context:

   --> pokemon-service-server-sdk/src/input.rs:813:58
    |
813 | ...                   message: format!("Value at '{}/events' failed to satisfy constraint: Member must not be null", path),
    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
help: change this to
    |
813 -                                                 message: format!("Value at '{}/events' failed to satisfy constraint: Member must not be null", path),
813 +                                                 message: format!("Value at '{path}/events' failed to satisfy constraint: Member must not be null"),
    |

This format string is rendered by a helper function like this. Therefore, it seems to take more than moving a variable name into a curly brace in the format! string.

To work around this temporarily, the server codegen allows uninlined_format_args in libRsCustomizations in ServerRequiredCustomizations. Remove this work around once the server codegen codebase is free from uninlined_format_args.

The issues were found in the following CI steps:

• check-server-codegen-integration-tests
• check-server-codegen-integration-tests-python
• check-server-e2e-test
• check-server-python-e2e-test

It's locally reproducible by removing the workaround above from libRsCustomizations and running ./gradlew codegen-server-test:test for instance.