[3.12] gh-129269: Exclude everything in sys.path in test_coverage_ignore (gh-130133) (gh-130358)

The `test_trace.test_coverage_ignore` test would fail if you had
`setuptools` installed, such as in `~/.local/lib/python3.xxx/site-packages/`.
Ignore everything in `sys.path` when running the test.
(cherry picked from commit 35925e9)

Author: colesbury

Lib/test/test_trace.py

@@ -390,7 +390,7 @@ def test_coverage_ignore(self):
         libpath = os.path.normpath(os.path.dirname(os.path.dirname(__file__)))
         # sys.prefix does not work when running from a checkout
         tracer = trace.Trace(ignoredirs=[sys.base_prefix, sys.base_exec_prefix,
-                             libpath], trace=0, count=1)
+                             libpath] + sys.path, trace=0, count=1)
         with captured_stdout() as stdout:
             self._coverage(tracer)
         if os.path.exists(TESTFN):