Auto merge of #17120 - gterzian:fix_double_borrowing_of_image_request, r=jdm

fix double borrowing of image request

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@jdm I couldn't reproduce the crashes, but looking at the code, I can tell that if we hit the cache inside `fetch_image`, we go straight to `process_image_response`, so we're still in the same scope as that where the borrowing occurs in `prepare_image_request`. When there is no cache hit, `process_image_response` is executed as part of a task...

This should fix the issue, while retaining the original logic.

All tests in `the-img-element` are passing...

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- [ ] `./mach build -d` does not report any errors
- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes fix #17109 (github issue number if applicable).

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- [ ] These changes do not require tests because _____

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components/script/dom/htmlimageelement.rs

@@ -524,22 +524,20 @@ impl HTMLImageElement {
                         }
                         self.image_request.set(ImageRequestPhase::Pending);
                         self.init_image_request(&mut pending_request, &url, &src);
-                        self.fetch_image(&url);
                     },
                     (_, State::Broken) | (_, State::Unavailable) => {
                         // Step 12.5
                         self.init_image_request(&mut current_request, &url, &src);
-                        self.fetch_image(&url);
                     },
                     (_, _) => {
                         // step 12.6
                         self.image_request.set(ImageRequestPhase::Pending);
                         self.init_image_request(&mut pending_request, &url, &src);
-                        self.fetch_image(&url);
                     },
                 }
             }
         }
+        self.fetch_image(&url);
     }
 
     /// Step 8-12 of html.spec.whatwg.org/multipage/#update-the-image-data