test: unmark tests that are no longer flaky

- `test-crypto-domains` was fixed by
joyent/node@2afa3d8a03

- All tests under linux appear to be fixed and have not failed recently
on Jenkins

- `test-http-dns-fail` was fixed by the DNS configuration change
mentioned in joyent/node#8056

Fixes #25656
Fixes #25673

Reviewed-By: Alexis Campailla <alexis@janeasystems.com>
PR-URL: https://github.com/joyent/node/pull/25676

test/internet/internet.status

@@ -3,4 +3,3 @@ prefix internet
 test-dns                          : PASS,FLAKY
 
 [$system==solaris]
-test-http-dns-fail                : PASS,FLAKY

test/simple/simple.status

@@ -1,6 +1,5 @@
 prefix simple
 
-test-crypto-domains               : PASS,FLAKY
 test-debug-signal-cluster         : PASS,FLAKY
 test-cluster-basic                : PASS,FLAKY
 test-microtask-queue-run          : PASS,FLAKY
@@ -10,10 +9,6 @@ test-microtask-queue-run-domain   : PASS,FLAKY
 test-timers-first-fire            : PASS,FLAKY
 
 [$system==linux]
-test-fs-readfile-error            : PASS,FLAKY
-test-net-GH-5504                  : PASS,FLAKY
-test-stdin-script-child           : PASS,FLAKY
-test-util-debug                   : PASS,FLAKY
 
 [$system==macos]
 test-fs-watch                     : PASS,FLAKY