Nano-optimize supervisor thread sleep

By avoiding .Bridge->.Num calls on SUPERVISION_INTERVAL
every 100th of a second. Pointless speed-wise, given we're sleeping
anyway, but it was polluting my Rat usage measurements data
by spamming .Bridge, .Num calls into the log.

src/core/Date.pm

@@ -223,7 +223,7 @@ multi sub sleep($seconds --> Nil) {
             take $seconds - 1e9 * ($seconds / 1e9).Int;
         }
     }
-    elsif $seconds > 0 {
+    elsif $seconds > 0e0 {
         nqp::sleep($seconds.Num);
     }
 }

src/core/ThreadPoolScheduler.pm

@@ -452,7 +452,7 @@ my class ThreadPoolScheduler does Scheduler {
     # The supervisor sits in a loop, mostly sleeping. Each time it wakes up,
     # it takes stock of the current situation and decides whether or not to
     # add threads.
-    my constant SUPERVISION_INTERVAL  = 0.01;
+    my constant SUPERVISION_INTERVAL  = 1e-2;
     my constant NUM_SAMPLES           = 5;
     my constant EXHAUSTED_RETRY_AFTER = 100;
     method !maybe-start-supervisor(--> Nil) {