Rename typing to mypy since we also have pyright (#1007)

tox.ini

@@ -1,17 +1,17 @@
 # Keep docs in sync with docs env and .readthedocs.yml.
 [gh-actions]
 python =
-    3.6: py36
+    3.6: py36, mypy
     3.7: py37
     3.8: py38, changelog
     3.9: py39, pyright
-    3.10: py310, manifest, typing, docs
+    3.10: py310, manifest, mypy, docs
     3.11: py311
     pypy-3: pypy3
 
 
 [tox]
-envlist = typing,pre-commit,py36,py37,py38,py39,py310,py311,pypy3,pyright,manifest,docs,pypi-description,changelog,coverage-report
+envlist = mypy,pre-commit,py36,py37,py38,py39,py310,py311,pypy3,pyright,manifest,docs,pypi-description,changelog,coverage-report
 isolated_build = True
 
 
@@ -89,8 +89,7 @@ skip_install = true
 commands = towncrier build --version UNRELEASED --draft
 
 
-[testenv:typing]
-basepython = python3.10
+[testenv:mypy]
 deps = mypy>=0.902
 commands =
     mypy src/attrs/__init__.pyi src/attr/__init__.pyi src/attr/_version_info.pyi src/attr/converters.pyi src/attr/exceptions.pyi src/attr/filters.pyi src/attr/setters.pyi src/attr/validators.pyi