rebase: remove "github.com/pkg/errors" from go.mod

There is no direct dependency on "github.com/pkg/errors" anymore, so it
can be removed from go.mod.

After running `go mod tidy`, the "github.com/pkg/errors" gets downgraded
to a version that is referenced in other depndencies. This was
unexpected, but seems needed.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

vendor/github.com/pkg/errors/Makefile

@@ -1,44 +0,0 @@
-PKGS := github.com/pkg/errors
-SRCDIRS := $(shell go list -f '{{.Dir}}' $(PKGS))
-GO := go
-
-check: test vet gofmt misspell unconvert staticcheck ineffassign unparam
-
-test: 
-	$(GO) test $(PKGS)
-
-vet: | test
-	$(GO) vet $(PKGS)
-
-staticcheck:
-	$(GO) get honnef.co/go/tools/cmd/staticcheck
-	staticcheck -checks all $(PKGS)
-
-misspell:
-	$(GO) get github.com/client9/misspell/cmd/misspell
-	misspell \
-		-locale GB \
-		-error \
-		*.md *.go
-
-unconvert:
-	$(GO) get github.com/mdempsky/unconvert
-	unconvert -v $(PKGS)
-
-ineffassign:
-	$(GO) get github.com/gordonklaus/ineffassign
-	find $(SRCDIRS) -name '*.go' | xargs ineffassign
-
-pedantic: check errcheck
-
-unparam:
-	$(GO) get mvdan.cc/unparam
-	unparam ./...
-
-errcheck:
-	$(GO) get github.com/kisielk/errcheck
-	errcheck $(PKGS)
-
-gofmt:  
-	@echo Checking code is gofmted
-	@test -z "$(shell gofmt -s -l -d -e $(SRCDIRS) | tee /dev/stderr)"