Remove reader lock

Author: MrLotU

Sources/CoreMetrics/Metrics.swift

@@ -390,14 +390,6 @@ public enum MetricsSystem {
         return try self.lock.withWriterLock(body)
     }
 
-    /// Acquire a reader lock for the duration of the given block.
-    ///
-    /// - Parameter body: The block to execute while holding the lock.
-    /// - Returns: The value returned by the block.
-    public static func withReaderLock<T>(_ body: () throws -> T) rethrows -> T {
-        return try self.lock.withReaderLock(body)
-    }
-
     /// `bootstrap` is an one-time configuration function which globally selects the desired metrics backend
     /// implementation. `bootstrap` can be called at maximum once in any given program, calling it more than once will
     /// lead to undefined behaviour, most likely a crash.