tox: Don't use environment names ending in digits

This fails now with 'failed with env name pyinstaller-32 conflicting with base python C:\hostedtoolcache\windows\Python\3.10.9\x86\python.exe'

See https://github.com/tox-dev/tox/pull/2824

scripts/dev/build_release.py

@@ -322,7 +322,7 @@ def build_mac(
                         gh_token=gh_token)
 
     utils.print_title("Building .app via pyinstaller")
-    call_tox('pyinstaller-64', '-r', debug=debug)
+    call_tox('pyinstaller-64bit', '-r', debug=debug)
     utils.print_title("Patching .app")
     patch_mac_app()
     utils.print_title("Re-signing .app")
@@ -404,7 +404,12 @@ def _build_windows_single(
     _maybe_remove(out_path)
 
     python = _get_windows_python_path(x64=x64)
-    call_tox(f'pyinstaller-{"64" if x64 else "32"}', '-r', python=python, debug=debug)
+    call_tox(
+        f'pyinstaller-{"64bit" if x64 else "32bit"}',
+        '-r',
+        python=python,
+        debug=debug,
+    )
 
     out_pyinstaller = dist_path / "qutebrowser"
     shutil.move(out_pyinstaller, out_path)

tox.ini

@@ -167,7 +167,7 @@ commands =
     {envpython} scripts/dev/check_doc_changes.py {posargs}
     {envpython} scripts/asciidoc2html.py {posargs}
 
-[testenv:pyinstaller-{64,32}]
+[testenv:pyinstaller-{64bit,32bit}]
 basepython = {env:PYTHON:python3}
 passenv =
     APPDATA