Fix --exlude typo in tox.ini

This commit corrects a typo recently introduced to update our language to
be more inclusive:

  https://review.opendev.org/c/openstack/tempest/+/768583

This typo is causing failures in neutron tempest runs.

Change-Id: I1d867dc0a1641a3c364984c5a91e301a2d938d01

tox.ini

@@ -136,7 +136,7 @@ deps = {[tempestenv]deps}
 commands =
     find . -type f -name "*.pyc" -delete
     tempest run --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.api)' --exclude-list ./tools/tempest-integrated-gate-networking-exclude-list.txt {posargs}
-    tempest run --combine --serial --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)' --exlude-list ./tools/tempest-integrated-gate-networking-exclude-list.txt {posargs}
+    tempest run --combine --serial --regex '(?!.*\[.*\bslow\b.*\])(^tempest\.scenario)' --exclude-list ./tools/tempest-integrated-gate-networking-exclude-list.txt {posargs}
 
 [testenv:integrated-compute]
 envdir = .tox/tempest