Fix legacy cb version in remapper

patches/server/0022-Remap-reflection-calls-in-plugins-using-internals.patch

@@ -608,7 +608,7 @@ index 0000000000000000000000000000000000000000..5fa5868e82d1f00498d0c5771369e171
 +    }
 +}
 diff --git a/src/main/java/io/papermc/paper/util/MappingEnvironment.java b/src/main/java/io/papermc/paper/util/MappingEnvironment.java
-index 8e4229634d41a42b3d93948eebb77def7c0c72b1..4d57213c9917ea965bfe06a5d242e61422457ee2 100644
+index 8e4229634d41a42b3d93948eebb77def7c0c72b1..2458685e7612040cea9d638dd2d945da1399ed77 100644
 --- a/src/main/java/io/papermc/paper/util/MappingEnvironment.java
 +++ b/src/main/java/io/papermc/paper/util/MappingEnvironment.java
 @@ -10,6 +10,8 @@ import org.checkerframework.framework.qual.DefaultQualifier;
@@ -616,7 +616,7 @@ index 8e4229634d41a42b3d93948eebb77def7c0c72b1..4d57213c9917ea965bfe06a5d242e614
  @DefaultQualifier(NonNull.class)
  public final class MappingEnvironment {
 +    public static final boolean DISABLE_PLUGIN_REWRITING = Boolean.getBoolean("paper.disable-plugin-rewriting");
-+    public static final String LEGACY_CB_VERSION = "v1_20_R4";
++    public static final String LEGACY_CB_VERSION = "v1_21_R1";
      private static final @Nullable String MAPPINGS_HASH = readMappingsHash();
      private static final boolean REOBF = checkReobf();