Do not instrument transmitter requests

Requests performed by the transmitter after the integration has been
initialised, such as those performed by the heartbeats module, were
being instrumented by OpenTelemetry. This commit uses `suppressTracing`
to prevent that.

Author: unflxw

.changesets/prevent-internal-appsignal-requests-from-being-instrumented.md

@@ -0,0 +1,6 @@
+---
+bump: patch
+type: fix
+---
+
+Prevent internal AppSignal requests from being instrumented and appearing in the "Slow API requests" panel.

src/transmitter.ts

@@ -6,6 +6,9 @@ import { Configuration } from "./config"
 import { URL, URLSearchParams } from "url"
 import { Client } from "./client"
 
+import { context } from "@opentelemetry/api"
+import { suppressTracing } from "@opentelemetry/core"
+
 const REDIRECT_COUNT = Symbol("redirect-count")
 
 type TransmitterRequestOptions = {
@@ -101,32 +104,34 @@ export class Transmitter {
   }
 
   public request(requestOptions: TransmitterRequestOptions) {
-    const { method, params = new URLSearchParams(), onError } = requestOptions
+    context.with(suppressTracing(context.active()), () => {
+      const { method, params = new URLSearchParams(), onError } = requestOptions
 
-    const initialOptions = {
-      method,
-      ...this.urlRequestOptions()
-    }
+      const initialOptions = {
+        method,
+        ...this.urlRequestOptions()
+      }
 
-    const { protocol, path } = initialOptions
+      const { protocol, path } = initialOptions
 
-    const options = {
-      ...initialOptions,
-      ...this.paramsRequestOptions(path ?? "", params),
-      ...this.bodyRequestOptions(method),
-      ...this.caRequestOptions(protocol ?? "")
-    }
+      const options = {
+        ...initialOptions,
+        ...this.paramsRequestOptions(path ?? "", params),
+        ...this.bodyRequestOptions(method),
+        ...this.caRequestOptions(protocol ?? "")
+      }
 
-    const module = this.requestModule(protocol ?? "")
+      const module = this.requestModule(protocol ?? "")
 
-    const callback = this.handleRedirectsCallback(requestOptions)
+      const callback = this.handleRedirectsCallback(requestOptions)
 
-    const request = module.request(options, callback)
+      const request = module.request(options, callback)
 
-    request.on("error", onError)
+      request.on("error", onError)
 
-    this.writeRequest(method, request)
-    request.end()
+      this.writeRequest(method, request)
+      request.end()
+    })
   }
 
   private handleRedirectsCallback({