Bump mypy from 1.8.0 to 1.9.0 in /Tools (#117418)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

Author: dependabot[bot]

Lib/test/libregrtest/main.py

@@ -349,9 +349,7 @@ def run_test(
             namespace = dict(locals())
             tracer.runctx(cmd, globals=globals(), locals=namespace)
             result = namespace['result']
-            # Mypy doesn't know about this attribute yet,
-            # but it will do soon: https://github.com/python/typeshed/pull/11091
-            result.covered_lines = list(tracer.counts)  # type: ignore[attr-defined]
+            result.covered_lines = list(tracer.counts)
         else:
             result = run_single_test(test_name, runtests)
 

Tools/requirements-dev.txt

@@ -1,6 +1,6 @@
 # Requirements file for external linters and checks we run on
 # Tools/clinic, Tools/cases_generator/, and Tools/peg_generator/ in CI
-mypy==1.8.0
+mypy==1.9.0
 
 # needed for peg_generator:
 types-psutil==5.9.5.20240316