Update to mypy 1

This commit will update to mypy 1. In the past, releases were managed by
Dropbox (python/mypy#12210), and were done at infrequent intervals. They
plan to release more regularly in the future.

Mypy does not keep a changelog, but did provide a 1.0 release blog post:
https://mypy-lang.blogspot.com/2023/02/mypy-10-released.html

A changelog has been requested (python/mypy#2859, python/mypy#13279),
but has been dismissed because "you can view the git history easily."

The new release versioning scheme is in the format `major.minor.patch`,
but is not SemVer-compliant, as explained in their blog post and wiki.
https://github.com/python/mypy/wiki/Release-Process

The update to mypy 1 was postponed until bug fixes were available in the
1.0.1 patch release (python/mypy#13685).

.pre-commit-config.yaml

@@ -16,7 +16,7 @@ repos:
       - id: isort
         args: [--filter-files]
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v0.991
+    rev: v1.0.1
     hooks:
       - id: mypy
         language: system

pyproject.toml

@@ -38,7 +38,7 @@ checks = [
   "black>=23,<24",
   "flake8>=6,<7",
   "isort>=5,<6",
-  "mypy==0.991",
+  "mypy==1.0.1",
   "pre-commit>=2,<3",
 ]
 docs = [