Suppress CI warnings for Python 3.12

- python-dateutil uses the deprecated datetime.utcfromtimestamp(); its
  next release after 2.8.2 will no longer use this function.
- Missing coverage is being falsely reported for an exit from a finally
  block; the coverage exclusion can be removed with python/cpython#105658.

pyproject.toml

@@ -34,6 +34,7 @@ no-cover-if-is-macos = "'darwin' == os_environ.get('COVERAGE_PLATFORM', sys_plat
 no-cover-if-not-macos = "'darwin' != os_environ.get('COVERAGE_PLATFORM', sys_platform) and os_environ.get('COVERAGE_EXCLUDE_PLATFORM') != 'disable'"
 no-cover-if-is-windows = "'win32' == os_environ.get('COVERAGE_PLATFORM', sys_platform) and os_environ.get('COVERAGE_EXCLUDE_PLATFORM') != 'disable'"
 no-cover-if-not-windows = "'win32' != os_environ.get('COVERAGE_PLATFORM', sys_platform) and os_environ.get('COVERAGE_EXCLUDE_PLATFORM') != 'disable'"
+no-cover-if-is-py312 = "python_version == '3.12' and os_environ.get('COVERAGE_EXCLUDE_PYTHON_VERSION') != 'disable'"
 no-cover-if-lt-py312 = "sys_version_info < (3, 12) and os_environ.get('COVERAGE_EXCLUDE_PYTHON_VERSION') != 'disable'"
 no-cover-if-is-py310 = "python_version == '3.10' and os_environ.get('COVERAGE_EXCLUDE_PYTHON_VERSION') != 'disable'"
 no-cover-if-lt-py310 = "sys_version_info < (3, 10) and os_environ.get('COVERAGE_EXCLUDE_PYTHON_VERSION') != 'disable'"
@@ -52,6 +53,8 @@ multi_line_output = 3
 testpaths = ["tests"]
 filterwarnings = [
     "error",
+    # suppress until python-dateutil>2.8.2 is released (https://github.com/dateutil/dateutil/issues/1284)
+    "ignore:.*datetime.utcfromtimestamp\\(\\) is deprecated.*:DeprecationWarning:",
 ]
 
 # need to ensure build directories aren't excluded from recursion

src/briefcase/platforms/macOS/__init__.py

@@ -575,7 +575,8 @@ def notarize(self, filename, team_id):
         finally:
             # Clean up house; we don't need the archive anymore.
             if archive_filename != filename:
-                self.tools.os.unlink(archive_filename)
+                # coverage exclusion required for https://github.com/python/cpython/issues/105658
+                self.tools.os.unlink(archive_filename)  # no-cover-if-is-py312
 
         try:
             self.logger.info()