Merge pull request #14111 from akyrtzi/disable-flaky-tests-5.0

[5.0]Disable two flaky tests

Author: akyrtzi

test/SourceKit/CursorInfo/cursor_no_cancel.swift

@@ -44,3 +44,6 @@ func myFunc() {
 // RANGE: source.lang.swift.range.singleexpression
 // RANGE: source.lang.swift.range.singleexpression
 // RANGE: source.lang.swift.range.singleexpression
+
+// FIXME: this crashes very infrequently in CI
+// REQUIRES: disabled

test/SwiftSyntax/VisitorTest.swift

@@ -3,6 +3,9 @@
 // REQUIRES: OS=macosx
 // REQUIRES: objc_interop
 
+// FIXME: This test fails occassionally in CI with invalid json.
+// REQUIRES: disabled
+
 import StdlibUnittest
 import Foundation
 import SwiftSyntax