fix usage with nix 2.15

[Artturin]

warning: The interpretation of store paths arguments ending in.drv recently changed. If this command is now failing try again with '/nix/store/m5raazy9x0zm8p732y001aqypds0hb2m-gebaar-libinput-+6ce14eb.drv^*'

this will break nix 2.15< but i don't know enough golang to make it conditional so help needed

fixes https://github.com/Mic92/nix-build-uncached/issues/52

There's most likely dozens of silently broken CI right now so it's important to get this in and to nixpkgs

[Mic92]

bors merge

[bors[bot]]

Build failed:

• tests (ubuntu-latest)

[Mic92]

bors merge

[bors[bot]]

Build succeeded:

• tests (macos-latest)
• tests (ubuntu-latest)