[minor] sort tox testenvs to ease finding one (#14904)

As the number grows starts to need search and wondering at what place to
add a new one. Making sorted makes the order obvious

tox.ini

@@ -6,9 +6,9 @@ envlist =
     py38,
     py39,
     py310,
+    docs,
     lint,
     type,
-    docs,
 isolated_build = true
 
 [testenv]
@@ -21,6 +21,23 @@ passenv =
 deps = -rtest-requirements.txt
 commands = python -m pytest {posargs}
 
+[testenv:dev]
+description = generate a DEV environment, that has all project libraries
+usedevelop = True
+deps =
+    -rtest-requirements.txt
+    -rdocs/requirements-docs.txt
+commands =
+    python -m pip list --format=columns
+    python -c 'import sys; print(sys.executable)'
+
+[testenv:docs]
+description = invoke sphinx-build to build the HTML docs
+deps = -rdocs/requirements-docs.txt
+commands =
+    sphinx-build -d "{toxworkdir}/docs_doctree" docs/source "{toxworkdir}/docs_out" --color -W -bhtml {posargs}
+    python -c 'import pathlib; print("documentation available under file://\{0\}".format(pathlib.Path(r"{toxworkdir}") / "docs_out" / "index.html"))'
+
 [testenv:lint]
 description = check the code style
 commands =
@@ -37,20 +54,3 @@ passenv =
 commands =
     python -m mypy --config-file mypy_self_check.ini -p mypy -p mypyc
     python -m mypy --config-file mypy_self_check.ini misc --exclude misc/fix_annotate.py --exclude misc/async_matrix.py --exclude misc/sync-typeshed.py
-
-[testenv:docs]
-description = invoke sphinx-build to build the HTML docs
-deps = -rdocs/requirements-docs.txt
-commands =
-    sphinx-build -d "{toxworkdir}/docs_doctree" docs/source "{toxworkdir}/docs_out" --color -W -bhtml {posargs}
-    python -c 'import pathlib; print("documentation available under file://\{0\}".format(pathlib.Path(r"{toxworkdir}") / "docs_out" / "index.html"))'
-
-[testenv:dev]
-description = generate a DEV environment, that has all project libraries
-usedevelop = True
-deps =
-    -rtest-requirements.txt
-    -rdocs/requirements-docs.txt
-commands =
-    python -m pip list --format=columns
-    python -c 'import sys; print(sys.executable)'