arrow

MINOR: Ignore direnv file .envrc (#35646)

Ignore .envrc files associated with the direnv[1] utility.

### Rationale for this change

There is no conflicting usage of .envrc in the arrow repo. 

### Are these changes tested?

Yes

### Are there any user-facing changes?

No

[1] https://direnv.net/

Authored-by: Dane Pitkin <dane@voltrondata.com>
Signed-off-by: Will Jones <willjones127@gmail.com>