Minor: Fix temporary files created but not deleted during testing

[2010YOUY01]

Which issue does this PR close?

NA

Rationale for this change

On the current main branch, some temporary testing files didn't get cleaned up after testing

> cargo test read_from_different_file_extension
> git status
Untracked files:
  (use "git add <file>..." to include in what will be committed)
        datafusion/core/output1.parquet
        datafusion/core/output2.parquet.snappy
        datafusion/core/output3.parquet.snappy.parquet

What changes are included in this PR?

Create those files under temporary directory, make sure they're cleaned up automatically afterwards

Are these changes tested?

No

Are there any user-facing changes?

[alamb]

I have noticed these files lately too -- thank you @2010YOUY01 for this cleanup!