testsuite: early shell error without version num

Problem: other commits in this PR allow version numbers other than 1,
so we need a different parameter in t2608 to cause early shell error

Modifies the early fatal error test in t2608 to use an integer instead
of required dictionary for '.attributes.system.environment'

t/t2608-job-shell-log.t

@@ -226,7 +226,7 @@ test_expect_success 'flux-shell: stdout/err from task.exec works' '
 test_expect_success 'flux-shell: early fatal errors are captured in eventlog' '
 	flux jobtap load alloc-bypass.so &&
 	id=$(flux run --dry-run -Salloc-bypass.R="$(flux resource R -i0)" true | \
-	     jq .version=2 | \
+	     jq '.attributes.system.environment=1' | \
 	     flux job submit --flags=novalidate) &&
 	echo jobid=$id &&
 	flux job wait-event -Hvt 30 $id clean &&