loader, iter, reflect: use build tags for package iter and iter methods on reflect.Value

Author: ydnar

Diff for: loader/goroot.go

@@ -261,10 +261,6 @@ func pathsToOverride(goMinor int, needsSyscallPackage bool) map[string]bool {
 		"unique/":                     false,
 	}
 
-	if goMinor <= 22 {
-		paths["iter]"] = false
-	}
-
 	if goMinor >= 19 {
 		paths["crypto/internal/"] = true
 		paths["crypto/internal/boring/"] = true

Diff for: src/iter/iter.go

@@ -1,3 +1,5 @@
+//go:build go1.23
+
 // Copyright 2024 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.