POC: Don't special case Python builtin and NumPy functions
- [ ] closes #xxxx (Replace xxxx with the GitHub issue number)
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

This PR is just to demonstrate the impact of #53425 on tests.

```
np.random.seed(26)
size = 100000
df = pd.DataFrame(
    {
        "a": 0,
        "b": np.random.random(size),
    }
)
gb = df.groupby("a")

# This PR
print(gb.agg("sum").iloc[0, 0])
# 50150.538337372185
print(gb.agg(np.sum).iloc[0, 0])
# 50150.53833737219

# main
print(gb.agg("sum").iloc[0, 0])
# 50150.538337372185
print(gb.agg(np.sum).iloc[0, 0])
# 50150.538337372185
This pull request is stale because it has been open for thirty days with no activity. Please [update](https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#updating-your-pull-request) and respond to this comment if you're still interested in working on this. Closing in favor of #53974