fix: exports failing intermittently due to tmp directory errors

[k-anshul]

Checklist:

• Covered by tests
• Ran it and it works as intended
• Reviewed the diff before requesting a review
• Checked for unhandled edge cases
• Linked the issues it closes
• Checked if the docs need to be updated. If so, create a separate Linear DOCS issue
• Intend to cherry-pick into the release branch
• I'm proud of this work!

[pjain1]

Can this be a sub directory inside tmpDir itself? Also if its a separate dir then lets defer os.RemoveAll(duckdbTmpDir) before defer duckdb.Close() so that first duckdb is closed first and then dir is removed.

[k-anshul]

Can this be a sub directory inside tmpDir itself?

It can be but felt better to isolate from sqlite db file which can also generate its own journal files/tmp files.

Also if its a separate dir then lets defer os.RemoveAll(duckdbTmpDir) before defer duckdb.Close() so that first duckdb is closed first and then dir is removed.

Sure.