test: remove references to unsupported AIX versions

The `filehandle.utimes()` and `fs.futimes()` work on all versions
of AIX that are supported by this version of Node.js.

Author: richardlau

doc/api/fs.md

@@ -420,9 +420,6 @@ added: v10.0.0
 Change the file system timestamps of the object referenced by the {FileHandle}
 then resolves the promise with no arguments upon success.
 
-This function does not work on AIX versions before 7.1, it will reject the
-promise with an error using code `UV_ENOSYS`.
-
 #### `filehandle.write(buffer[, offset[, length[, position]]])`
 <!-- YAML
 added: v10.0.0
@@ -2329,9 +2326,6 @@ changes:
 Change the file system timestamps of the object referenced by the supplied file
 descriptor. See [`fs.utimes()`][].
 
-This function does not work on AIX versions before 7.1, it will return the
-error `UV_ENOSYS`.
-
 ### `fs.lchmod(path, mode, callback)`
 <!-- YAML
 deprecated: v0.4.7

test/parallel/test-trace-events-fs-sync.js

@@ -124,13 +124,6 @@ for (const tr in tests) {
                               '--trace-event-categories', 'node.fs.sync',
                               '-e', tests[tr] ],
                             { cwd: tmpdir.path, encoding: 'utf8' });
-  // Some AIX versions don't support futimes or utimes, so skip.
-  if (common.isAIX && proc.status !== 0 && tr === 'fs.sync.futimes') {
-    continue;
-  }
-  if (common.isAIX && proc.status !== 0 && tr === 'fs.sync.utimes') {
-    continue;
-  }
 
   // Make sure the operation is successful.
   // Don't use assert with a custom message here. Otherwise the