main/fish: remove minikube completion

it's now provided by the minikube-fish-completion package
7 jobs for !20493 with fish-minikube in 6 minutes and 8 seconds (queued for 1 second)
detached
Status Job ID Name Coverage
  Lint
passed #371751
docker-alpine x86_64
lint

00:00:18

 
  Build
passed #371756
docker-alpine ci-build aarch64
build-aarch64

00:01:45

passed #371757
docker-alpine ci-build armv7
build-armv7

00:01:22

passed #371755
docker-alpine ci-build ppc64le
build-ppc64le

00:01:37

passed #371754
docker-alpine ci-build s390x
build-s390x

00:01:35

passed #371753
docker-alpine ci-build x86
build-x86

00:03:17

passed #371752
docker-alpine ci-build x86_64
build-x86_64

00:00:39