Auto merge of #29671 - Loirooriol:update-2020-expectations, r=mrobinson

Update layout-2020 test expectations

Some tests are now passing thanks to #29661.

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

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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because they are just updating test expectations.

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tests/wpt/metadata-layout-2020/css/css-flexbox/negative-overflow.html.ini

@@ -5,9 +5,6 @@
   [.flexbox 11]
     expected: FAIL
 
-  [.flexbox 5]
-    expected: FAIL
-
   [.flexbox 6]
     expected: FAIL
 
@@ -28,6 +25,3 @@
 
   [.flexbox 9]
     expected: FAIL
-
-  [.flexbox 4]
-    expected: FAIL

tests/wpt/metadata-layout-2020/css/css-flexbox/overflow-auto-008.html.ini

@@ -1,3 +0,0 @@
-[overflow-auto-008.html]
-  [hbox dimensions]
-    expected: FAIL

tests/wpt/metadata-layout-2020/css/css-masking/clip/clip-rect-scroll.html.ini

@@ -1,2 +0,0 @@
-[clip-rect-scroll.html]
-  expected: FAIL