disable BigInt tests on all targets

tests/unit/src/unit/TestMain.hx

@@ -68,9 +68,9 @@ function main() {
 		#if (!php && !lua)
 		new TestHttps(),
 		#end
-		#if (!lua && !interp && !flash)
-		new TestBigInt(),
-		#end
+		/* Every target struggles with these tests. We can occasionally enable them when
+			making related changes, but otherwise this is not worth the CI time. */
+		// new TestBigInt(),
 		#if !no_pattern_matching
 		new TestMatch(),
 		#end