Bug 1668729 - Disable GC zeal for Environment-getVariable-13.js to fix intermittent failures. r=jonco

The test is asserting that certain code runs in Ion.

Differential Revision: https://phabricator.services.mozilla.com/D92549

js/src/jit-test/tests/debug/Environment-getVariable-13.js

@@ -5,6 +5,9 @@
 
 load(libdir + "jitopts.js");
 
+// GCs can invalidate JIT code and cause this test to fail.
+gczeal(0);
+
 if (!jitTogglesMatch(Opts_Ion2NoOffthreadCompilation))
   quit(0);