chore: disabling metrics for libwaku (#3058)

waku.nimble

@@ -63,12 +63,12 @@ proc buildLibrary(name: string, srcDir = "./", params = "", `type` = "static") =
     extra_params &= " " & paramStr(i)
   if `type` == "static":
     exec "nim c" & " --out:build/" & name &
-      ".a --threads:on --app:staticlib --opt:size --noMain --mm:refc --header " &
+      ".a --threads:on --app:staticlib --opt:size --noMain --mm:refc --header --undef:metrics " &
       extra_params & " " & srcDir & name & ".nim"
   else:
     exec "nim c" & " --out:build/" & name &
-      ".so --threads:on --app:lib --opt:size --noMain --mm:refc --header " & extra_params &
-      " " & srcDir & name & ".nim"
+      ".so --threads:on --app:lib --opt:size --noMain --mm:refc --header --undef:metrics " &
+      extra_params & " " & srcDir & name & ".nim"
 
 proc buildMobileAndroid(srcDir = ".", params = "") =
   let cpu = getEnv("CPU")

waku/waku_core/time.nim

@@ -18,7 +18,9 @@ proc nowInUnixFloat(): float =
 proc getNowInNanosecondTime*(): Timestamp =
   return getNanosecondTime(nowInUnixFloat())
 
-template nanosecondTime*(collector: Summary | Histogram, body: untyped) =
+template nanosecondTime*(
+    collector: Summary | Histogram | typedesc[IgnoredCollector], body: untyped
+) =
   when defined(metrics):
     let start = nowInUnixFloat()
     body

waku/waku_rln_relay/protocol_metrics.nim

@@ -80,9 +80,11 @@ proc getRlnMetricsLogger*(): RLNMetricsLogger =
   var cumulativeValidMessages = 0.float64
   var cumulativeProofs = 0.float64
 
+  when defined(metrics):
     logMetrics = proc() =
       {.gcsafe.}:
-      let freshErrorCount = parseAndAccumulate(waku_rln_errors_total, cumulativeErrors)
+        let freshErrorCount =
+          parseAndAccumulate(waku_rln_errors_total, cumulativeErrors)
         let freshMsgCount =
           parseAndAccumulate(waku_rln_messages_total, cumulativeMessages)
         let freshSpamCount =