resolve code-scanning#2 (#1631)

Author: plantfansam

metrics_api/lib/opentelemetry/metrics/meter.rb

@@ -15,7 +15,7 @@ class Meter
       UP_DOWN_COUNTER = Instrument::UpDownCounter.new
       OBSERVABLE_UP_DOWN_COUNTER = Instrument::ObservableUpDownCounter.new
 
-      NAME_REGEX = /^[a-zA-Z][-.\w]{0,62}$/
+      NAME_REGEX = /\A[a-zA-Z][-.\w]{0,62}\z/
 
       private_constant(:COUNTER, :OBSERVABLE_COUNTER, :HISTOGRAM, :OBSERVABLE_GAUGE, :UP_DOWN_COUNTER, :OBSERVABLE_UP_DOWN_COUNTER)