gh-72463: Fix Lib/ctypes/test_loading.py so that test_find reports skipped

[aixtools]

Fix Lib/ctypes/test_loading.py so that test_find reports skipped rather than passed when no libraries to test are found.

Backport to 3.7 and 3.8 is requested.

https://bugs.python.org/issue28276

• Issue: test_loading.py - false positive result for "def test_find" when find_library() is not functional or the (shared) library does not exist #72463

[aixtools]

I know this is not "urgent" - but it always struck me as strange that a function that always returns NULL - when something, at least once, is expected - should pass - when perhaps the function has failed every time .

[serhiy-storchaka]

LGTM. I fixed an error and removed a NEWS entry which is not required for such kind of changes.

[miss-islington-app]

Thanks @aixtools for the PR, and @serhiy-storchaka for merging it 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖

[bedevere-app]

GH-116136 is a backport of this pull request to the 3.12 branch.

[bedevere-app]

GH-116137 is a backport of this pull request to the 3.11 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Debian root 3.11 has failed when building commit 8643cfd.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/1007/builds/1416) and take a look at the build logs.
4. Check if the failure is related to this commit (8643cfd) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/1007/builds/1416

Summary of the results of the build (if available):

==

Click to see traceback logs

remote: Enumerating objects: 6, done.        
remote: Counting objects:  16% (1/6)        
remote: Counting objects:  33% (2/6)        
remote: Counting objects:  50% (3/6)        
remote: Counting objects:  66% (4/6)        
remote: Counting objects:  83% (5/6)        
remote: Counting objects: 100% (6/6)        
remote: Counting objects: 100% (6/6), done.        
remote: Compressing objects:  25% (1/4)        
remote: Compressing objects:  50% (2/4)        
remote: Compressing objects:  75% (3/4)        
remote: Compressing objects: 100% (4/4)        
remote: Compressing objects: 100% (4/4), done.        
remote: Total 6 (delta 2), reused 5 (delta 2), pack-reused 0        
From https://github.com/python/cpython
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HEAD is now at 8643cfd918 [3.11] gh-72463: Fix ctypes/test_loading.py so that test_find reports skipped (GH-18312) (GH-116137)
Switched to and reset branch '3.11'

configure: WARNING: pkg-config is missing. Some dependencies may not be detected correctly.

renaming build/scripts-3.11/pydoc3 to build/scripts-3.11/pydoc3.11
renaming build/scripts-3.11/idle3 to build/scripts-3.11/idle3.11
renaming build/scripts-3.11/2to3 to build/scripts-3.11/2to3-3.11

renaming build/scripts-3.11/pydoc3 to build/scripts-3.11/pydoc3.11
renaming build/scripts-3.11/idle3 to build/scripts-3.11/idle3.11
renaming build/scripts-3.11/2to3 to build/scripts-3.11/2to3-3.11

renaming build/scripts-3.11/pydoc3 to build/scripts-3.11/pydoc3.11
renaming build/scripts-3.11/idle3 to build/scripts-3.11/idle3.11
renaming build/scripts-3.11/2to3 to build/scripts-3.11/2to3-3.11
make: *** [Makefile:1846: buildbottest] Error 3