fix: use Go 1.25 in CI workflows

Updated GO_VERSION from 1.23 to 1.25 in both build.yml and pr-checks.yml.
Reverted Makefile lint targets to use default settings since Go 1.25
supports GOEXPERIMENT=jsonv2.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -13,7 +13,7 @@ on:
 
 env:
   GOPROXY: https://proxy.golang.org,direct
-  GO_VERSION: "1.23"
+  GO_VERSION: "1.25"
   NODE_VERSION: "22"
 
 jobs:

.gitea/workflows/pr-checks.yml

@@ -8,7 +8,7 @@ on:
 
 env:
   GOPROXY: https://proxy.golang.org,direct
-  GO_VERSION: "1.23"
+  GO_VERSION: "1.25"
   NODE_VERSION: "22"
 
 jobs:

Makefile

@@ -377,11 +377,11 @@ lint-spell-fix: ## lint spelling and fix issues
 
 .PHONY: lint-go
 lint-go: ## lint go files
-	GOEXPERIMENT= GOTOOLCHAIN=local $(GO) run $(GOLANGCI_LINT_PACKAGE) run
+	$(GO) run $(GOLANGCI_LINT_PACKAGE) run
 
 .PHONY: lint-go-fix
 lint-go-fix: ## lint go files and fix issues
-	GOEXPERIMENT= GOTOOLCHAIN=local $(GO) run $(GOLANGCI_LINT_PACKAGE) run --fix
+	$(GO) run $(GOLANGCI_LINT_PACKAGE) run --fix
 
 # workaround step for the lint-go-windows CI task because 'go run' can not
 # have distinct GOOS/GOARCH for its build and run steps