Disable record_metrics_slice in grafana macro on wasm (#4312)

* Disable record_metrics_slice in grafana macro on wasm

* Update client/grafana-data-source/src/lib.rs

* Revert "Update client/grafana-data-source/src/lib.rs"

This reverts commit 888009a8e0b7051bd4bfbbfdb0448bcf2e2aae93.

substrate/client/grafana-data-source/src/lib.rs

@@ -47,9 +47,13 @@ lazy_static! {
 #[macro_export]
 macro_rules! record_metrics(
 	($($key:expr => $value:expr,)*) => {
-		$crate::record_metrics_slice(&[
-			$( ($key, $value as f32), )*
-		]);
+		if cfg!(not(target_os = "unknown")) {
+			$crate::record_metrics_slice(&[
+				$( ($key, $value as f32), )*
+			])
+		} else {
+			Ok(())
+		}
 	}
 );