[7.4.0] Don't HTML escape bazel mod JSON output (#23819)

Otherwise `"<root>"` ends up being escaped with Unicode escape
sequences, which is unnecessarily complex.

Work towards #22691

Closes #23785.

PiperOrigin-RevId: 680633877
Change-Id: Ic3c90c33bbf1209efa90be78b432e2132f0a1f05

Commit
e959d78

Co-authored-by: Fabian Meumertzheim <fabian@meumertzhe.im>

src/main/java/com/google/devtools/build/lib/bazel/bzlmod/modcommand/JsonOutputFormatter.java

@@ -44,7 +44,8 @@ public void output() {
     seenExtensions = new HashSet<>();
     JsonObject root = printModule(ModuleKey.ROOT, null, IsExpanded.TRUE, IsIndirect.FALSE);
     root.addProperty("root", true);
-    printer.println(new GsonBuilder().setPrettyPrinting().create().toJson(root));
+    printer.println(
+        new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create().toJson(root));
   }
 
   public String printKey(ModuleKey key) {