stress2: Enable two hwpmc tests that now run as expected

tools/test/stress2/misc/all.exclude

@@ -50,8 +50,6 @@ nfs16.sh		panic: Failed to register NFS lock locally - error=11		20160608
 nullfs28.sh		Hang in "mount drain" seen					20220111
 oom2.sh			Hang in pfault							20180324
 overcommit2.sh		CAM stuck in vmwait seen					20200112
-pmc4.sh			https://people.freebsd.org/~pho/stress/log/log0548.txt		20240904
-pmc8.sh			panic: [pmc,2749] (ri21, rc1) waiting too long for pmc to ...	20210621
 sctp2.sh		panic: Queues are not empty when handling SHUTDOWN-COMPLETE	20210211
 sctp3.sh		panic: Queues are not empty when handling SHUTDOWN-COMPLETE	20210211
 signal.sh		Timing issues. Needs fixing					20171116