Fix options for RTDB on node (#6399)

* Don't shadow options

* Add changeset

Author: jsdt

.changeset/stale-pianos-buy.md

@@ -0,0 +1,5 @@
+---
+'@firebase/database': patch
+---
+
+Fix setting of headers on Node.

packages/database/src/realtime/WebSocketConnection.ts

@@ -166,7 +166,7 @@ export class WebSocketConnection implements Transport {
       if (isNodeSdk()) {
         const device = this.nodeAdmin ? 'AdminNode' : 'Node';
         // UA Format: Firebase/<wire_protocol>/<sdk_version>/<platform>/<device>
-        const options: { [k: string]: object } = {
+        options = {
           headers: {
             'User-Agent': `Firebase/${PROTOCOL_VERSION}/${SDK_VERSION}/${process.platform}/${device}`,
             'X-Firebase-GMPID': this.applicationId || ''