Print error if deleting a non-existent thing

[bbkane]

$ envelope env delete --name thisdoesntexist
Type 'yes' to continue: yes
deleted: thisdoesntexist

Oopsie

[bbkane]

https://docs.sqlc.dev/en/latest/reference/query-annotations.html#execrows

[bbkane]

Hmm when I try to delete a non-existent var , I see an error about about a non-existent env...

[bbkane]

lol the non-existent var was in the non-existent env... it all works now... closing.