Remove goimports_vendorlesspath overlay to fix counterfeiter conflict

The hack/overlays/goimports_vendorlesspath.go overlay was causing
conflicts with counterfeiter mock generation because the vendored
golang.org/x/tools/imports now includes VendorlessPath function.

This overlay is no longer needed as the function is now available
in the vendored dependency.

Fixes: make verify counterfeiter errors

Author: jianzhangbjz

Makefile

@@ -340,11 +340,7 @@ mockgen: #HELP Generate mocks
 	# Consider using counterfeiter:generate directives to speed things up.
 	# See https://github.com/maxbrunsfeld/counterfeiter#step-2b---add-counterfeitergenerate-directives for more information.
 	# Set the "COUNTERFEITER_NO_GENERATE_WARNING" environment variable to suppress this message.
-	@set -e; \
-	overlay_file=$$(mktemp "$(CURDIR)/hack/overlays/goimports_overlay.XXXXXX.json"); \
-	trap 'rm -f "$$overlay_file"' EXIT; \
-	printf '{\n  "Replace": {\n    "%s/vendor/golang.org/x/tools/imports/vendorlesspath.go": "%s/hack/overlays/goimports_vendorlesspath.go"\n  }\n}\n' "$(CURDIR)" "$(CURDIR)" > "$$overlay_file"; \
-	GO111MODULE=on GOWORK=off COUNTERFEITER_NO_GENERATE_WARNING=1 GOFLAGS="$$GOFLAGS -overlay=$$overlay_file" go generate ./pkg/...
+	GO111MODULE=on GOWORK=off COUNTERFEITER_NO_GENERATE_WARNING=1 go generate ./pkg/...
 
 #SECTION Verification