geonix41のビルド時に出るwarningについて

ビルド時にシンボルサイズの差違でwarningが出ている。パッチを当てたせいだと思うが念のため調査し、issueとして記録する。

既知の問題であれば...
- PRを作成しないこと
- 経緯についてコメント

```
Linking: .build/windmill_geonix41_default.elf [WARNINGS]
|
| /opt/qmk/bin/../lib/gcc/arm-none-eabi/15.2.0/../../../../arm-none-eabi/bin/ld: warning: size of symbol `es_user_driver' changed from 20 in .build/obj_windmill_geonix41_default/keyboards/windmill/geonix41/geonix41.o to 24 in lib/rdr_lib/librdrcommon.a(rdr_common.o)
| /opt/qmk/bin/../lib/gcc/arm-none-eabi/15.2.0/../../../../arm-none-eabi/bin/ld: warning: NOTE: size discrepancies can cause real problems. Investigation is advised.
|
```

Start by reproducing the geonix41 build and reviewing the linker warning for es_user_driver. Compare the symbol definitions in geonix41.o and lib/rdr_lib/librdrcommon.a(rdr_common.o), then determine whether the patch caused the size mismatch. Done means recording the investigation and, if it is a known issue, commenting on its history without opening a PR.

Written by the indexing model from the issue text.