Also filter out netfs: messages when nfs tests run.

On el10, the kernel by default probes netfs while doing nfs
setup, and emits:

```
    netfs: FS-Cache loaded
```

Squelch it in filters.

Signed-off-by: Auke Kok <auke.kok@versity.com>

tests/funcs/filter.sh

@@ -178,6 +178,7 @@ t_filter_dmesg()
 	re="$re|NFSD: .*"
 	re="$re|RPC: .*"
 	re="$re|FS-Cache: .*"
+	re="$re|netfs: .*"
 
 	# fencing tests force unmounts and trigger timeouts
 	re="$re|scoutfs .* forcing unmount"