Auto merge of #13467 - JanZerebecki:rm-same-origin-data-url, r=KiChjang

Remove same-origin-data-url flag from fetch implementation

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The spec removed it. Check the scheme instead, data is always same origin now,
except for workers.
Closes #13362

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #13362 .

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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because they only remove code.

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tests/unit/net/fetch.rs

@@ -144,7 +144,6 @@ fn test_fetch_data() {
     let url = Url::parse("data:text/html,<p>Servo</p>").unwrap();
     let origin = Origin::Origin(url.origin());
     let request = Request::new(url, Some(origin), false, None);
-    request.same_origin_data.set(true);
     let expected_resp_body = "<p>Servo</p>".to_owned();
     let fetch_response = fetch_sync(request, None);
 
@@ -173,7 +172,6 @@ fn test_fetch_file() {
     let url = Url::from_file_path(path.clone()).unwrap();
     let origin = Origin::Origin(url.origin());
     let request = Request::new(url, Some(origin), false, None);
-    request.same_origin_data.set(true);
 
     let fetch_response = fetch_sync(request, None);
     assert!(!fetch_response.is_network_error());