Try to fix macOS another way.

.github/workflows/ci.yml

@@ -216,6 +216,11 @@ jobs:
         run: python misc/build_helpers/show-tool-versions.py
 
       - name: Run "Python 3 integration tests"
+        env:
+          # On macOS this is necessary to ensure unix socket paths for tor
+          # aren't too long. On Windows tox won't pass it through so it has no
+          # effect. On Linux it doesn't make a difference one way or another.
+          TMPDIR: "/tmp"
         run: tox -e integration
 
       - name: Upload eliot.log in case of failure

tox.ini

@@ -92,8 +92,6 @@ platform = mylinux: linux
            mywindows: win32
 setenv =
          COVERAGE_PROCESS_START=.coveragerc
-         # Without this, temporary file paths are too long on macOS, breaking tor
-         mymacos: TMPDIR=/tmp
 commands =
          # NOTE: 'run with "py.test --keep-tempdir -s -v integration/" to debug failures'
          py.test --timeout=1800 --coverage -v {posargs:integration}