[GTK] Undeprecate and document webkit_print_operation_print() behavior

https://bugs.webkit.org/show_bug.cgi?id=274456

Reviewed by Carlos Garcia Campos.

Turns out, there might be legitimate use cases for webkit_print_operation_print()
for sandboxed apps. However, they're very specific, and this function only works
in very specific situations.

Document that, and undeprecate the function.

* Source/WebKit/UIProcess/API/gtk/WebKitPrintOperation.cpp:
* Source/WebKit/UIProcess/API/gtk/WebKitPrintOperation.h.in:

Canonical link: https://commits.webkit.org/279054@main

Source/WebKit/UIProcess/API/gtk/WebKitPrintOperation.cpp

@@ -871,7 +871,10 @@ static GRefPtr<GtkPrinter> printerFromSettingsOrDefault(GtkPrintSettings* settin
  * operation finishes. If an error occurs while printing the signal
  * #WebKitPrintOperation::failed is emitted before #WebKitPrintOperation::finished.
  *
- * Deprecated: 2.46. This function does nothing if the app is sandboxed.
+ * If the app is running in a sandbox, this function only works if printing to
+ * a file that is in a location accessible to the sandbox, usually acquired
+ * through the File Chooser portal. This function will not work for physical
+ * printers when running in a sandbox.
  */
 void webkit_print_operation_print(WebKitPrintOperation* printOperation)
 {

Source/WebKit/UIProcess/API/gtk/WebKitPrintOperation.h.in

@@ -83,7 +83,7 @@ WEBKIT_API WebKitPrintOperationResponse
 webkit_print_operation_run_dialog         (WebKitPrintOperation *print_operation,
                                            GtkWindow            *parent);
 
-WEBKIT_DEPRECATED void
+WEBKIT_API void
 webkit_print_operation_print              (WebKitPrintOperation *print_operation);
 
 G_END_DECLS