chore: Make Forgejo build with go1.24

- [Go 1.24](https://groups.google.com/g/golang-announce/c/vYMfuq_XO6w)
is currently out for rc1.
- Using it to test unit tests and integration testing it failed horribly
with strange panics and errors, it is caused by
https://github.com/golang/go/commit/ca63101df47a4467bc80faa654fc19d68e583952
and Forgejo trying to access the wrong internal data structures that
have been changed in Go 1.24.
- Use the new data structure for Go 1.24 and above.

modules/log/groutinelabel.go

@@ -1,3 +1,5 @@
+//go:build !go1.24
+
 // Copyright 2022 The Gitea Authors. All rights reserved.
 // SPDX-License-Identifier: MIT
 

modules/log/groutinelabel_go1.24.go

@@ -0,0 +1,38 @@
+//go:build go1.24
+
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package log
+
+import "unsafe"
+
+//go:linkname runtime_getProfLabel runtime/pprof.runtime_getProfLabel
+func runtime_getProfLabel() unsafe.Pointer //nolint
+
+// Struct definitions copied from: https://github.com/golang/go/blob/ca63101df47a4467bc80faa654fc19d68e583952/src/runtime/pprof/label.go
+type label struct {
+	key   string
+	value string
+}
+
+type LabelSet struct {
+	list []label
+}
+
+type labelMap struct {
+	LabelSet
+}
+
+func getGoroutineLabels() map[string]string {
+	l := (*labelMap)(runtime_getProfLabel())
+	if l == nil {
+		return nil
+	}
+
+	m := make(map[string]string, len(l.list))
+	for _, label := range l.list {
+		m[label.key] = label.value
+	}
+	return m
+}