unittests: optimize IS_CI checks

Since IS_CI is a boolean instead of a function, it's slightly faster to
check that before other things

unittests/allplatformstests.py

@@ -2320,7 +2320,7 @@ class AllPlatformTests(BasePlatformTests):
     # Call this method before file operations in appropriate places
     # to make things work.
     def mac_ci_delay(self):
-        if is_osx() and IS_CI:
+        if IS_CI and is_osx():
             import time
             time.sleep(1)
 

unittests/helpers.py

@@ -208,7 +208,7 @@ def skip_if_env_set(key: str) -> T.Callable[[T.Callable[P, R]], T.Callable[P, R]
     def wrapper(func: T.Callable[P, R]) -> T.Callable[P, R]:
         @functools.wraps(func)
         def wrapped(*args: P.args, **kwargs: P.kwargs) -> R:
-            if key in os.environ and not IS_CI:
+            if not IS_CI and key in os.environ:
                 raise unittest.SkipTest(f'Env var {key!r} set, skipping')
             with mock.patch.dict(os.environ):
                 os.environ.pop(key, None)

unittests/windowstests.py

@@ -373,10 +373,10 @@ class WindowsTests(BasePlatformTests):
             raise SkipTest('Compiler does not support setting the VS CRT')
         # Verify that qmake is for Qt5
         if not shutil.which('qmake-qt5'):
-            if not shutil.which('qmake') and not IS_CI:
+            if not IS_CI and not shutil.which('qmake'):
                 raise SkipTest('QMake not found')
             output = subprocess.getoutput('qmake --version')
-            if 'Qt version 5' not in output and not IS_CI:
+            if not IS_CI and 'Qt version 5' not in output:
                 raise SkipTest('Qmake found, but it is not for Qt 5.')
         # Setup with /MDd
         testdir = os.path.join(self.framework_test_dir, '4 qt')