Clear more temporary file paths from env

This supplements clearing TMPDIR env variable which is only one among variables used for storing temporary files. Any of those leaking from host may confuse flatpak apps which try to save temporary files under non-existing directory in sandbox.

See https://github.com/flathub/com.logseq.Logseq/issues/29 for real world example.
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f