Bump mozrunner version to 8.3.1.

Differential Revision: https://phabricator.services.mozilla.com/D208604

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1893190
gecko-commit: b743d99059effb91581a29dcf6595a01d5c1716d
gecko-reviewers: perftest-reviewers, jgraham, sparky

Author: lutien

tools/wpt/requirements_android.txt

@@ -1 +1 @@
-mozrunner==8.3.0
+mozrunner==8.3.1

tools/wptrunner/requirements_firefox.txt

@@ -4,7 +4,7 @@ mozdevice==4.1.1
 mozinstall==2.1.0
 mozleak==0.2
 mozprofile==3.0.0
-mozrunner==8.3.0
+mozrunner==8.3.1
 mozversion==2.4.0
 psutil==5.9.5
 redo==2.0.4