adopt golangci-lint v2 (#31222)

* adopt golangci-lint v2

No actual linting changes in this commit, just upgraded tooling and
directives to ignore new linter rules. Adopting v2 solves some
gosec issues in v1 and also happens to be a nice performance boost!
As part of this PR, we also drop support for `MM_NO_ENTERPRISE_LINT`
which hasn't been need for a while anyway.

* simplify: go install is fine!

* missing GOBIN

* golangci-lint: drop legacy preset exclusion

server/Makefile

@@ -300,15 +300,11 @@ golang-versions: ## Install Golang versions used for compatibility testing (e.g.
 	export GO_COMPATIBILITY_TEST_VERSIONS="${GO_COMPATIBILITY_TEST_VERSIONS}"
 
 golangci-lint: ## Run golangci-lint on codebase
-	$(GO) install github.com/golangci/golangci-lint/cmd/golangci-lint@v1.64.7
-
-	@echo Running golangci-lint
-	$(GOBIN)/golangci-lint run ./...
-	$(GOBIN)/golangci-lint run ./public/...
+	$(GO) install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.1.6
 ifeq ($(BUILD_ENTERPRISE_READY),true)
-  ifneq ($(MM_NO_ENTERPRISE_LINT),true)
-		$(GOBIN)/golangci-lint run $(BUILD_ENTERPRISE_DIR)/...
-  endif
+	$(GOBIN)/golangci-lint run ./... ./public/... $(BUILD_ENTERPRISE_DIR)/...
+else
+	$(GOBIN)/golangci-lint run ./... ./public/...
 endif
 
 i18n-extract: ## Extract strings for translation from the source code