t: add default for test of invalid qmanager policy

Problem: the example config files for tests in t/conf.d includes
an example of invalid policy settings, both for match-policy in
resource and queue-policy in fluxion. This configuration is only used
in t1005, where qmanager is tested to ensure it tolerates an invalid
queue policy and defaults to fcfs.

Recently, the resource module was updated to not tolerate invalid
policies, but this shouldn't change the behavior of qmanager. Use
first in the sched-fluxion-resource toml file example for this
test.

t/conf.d/09-invalid-policy/sched-fluxion-resource.toml

@@ -1,6 +1,6 @@
 [sched-fluxion-resource]
 
-match-policy = "invalid"
+match-policy = "first"
 load-allowlist="node,core,gpu"
 reserve-vtx-vec=200000
 prune-filters="ALL:core,ALL:gpu"