Funannotate: fix for missing env var

[abretaud]

FOR CONTRIBUTOR:

• - I have read the CONTRIBUTING.md document and this tool is appropriate for the tools-iuc repo.
• - License permits unrestricted use (educational + commercial)
• - This PR adds a new tool or tool collection
• - This PR updates an existing tool or tool collection
• - This PR does something else (explain below)

Fill an env var needed by some subprocess. Problem reported upstream in nextgenusfs/funannotate#905

[bernt-matthias]

Looks good to me. Just wondering if its possible to add a test case that would fail wo the env variable. This would allow us to more confidently remove the env variable again once its fixed upstream.

If not I'm fine with merging.

[abretaud]

Arf, it would be painful to create the data for a test case here, but I'm preparing a worflow test in GTN that should test this situation

[bernt-matthias]

I'm preparing a worflow test in GTN that should test this situation

Good enough for me :)

Lets merge