CI/STYLE extend codespell beyond pandas/core
There is task left here:

1. apply the following diff
```diff
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index d78c2bacc..bcb9202d4 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -173,4 +173,4 @@ repos:
     hooks:
     -   id: codespell
         types_or: [python, rst, markdown]
         files: ^(pandas|doc)/
-        exclude: ^pandas/tests/
```
, run `pre-commit run codespell --all-files`, and fixup the mistakes 


You _may_ need you to add new words to ignore in `setup.cfg`.