Delete an unused internal field.

PiperOrigin-RevId: 811032599
diff --git a/java/core/src/main/java/com/google/protobuf/Internal.java b/java/core/src/main/java/com/google/protobuf/Internal.java
index d548cca..59dfc23 100644
--- a/java/core/src/main/java/com/google/protobuf/Internal.java
+++ b/java/core/src/main/java/com/google/protobuf/Internal.java
@@ -32,7 +32,6 @@
 
   private Internal() {}
 
-  static final Charset US_ASCII = Charset.forName("US-ASCII");
   static final Charset UTF_8 = Charset.forName("UTF-8");
   static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");