Make tests resilient to new Node default connection header changes

It seems that Node v20.5.1 sets this to keep-alive by default, but not
in all environments? Seeing keep-alive in GitHub but not locally with
the same release.

Doesn't matter for this test, best to just ignore it.

test/integration/subscriptions/request-events.spec.ts

@@ -26,6 +26,9 @@ const INCONSISTENT_HEADERS = [
     'origin',
     'referer',
 
+    // Varies on browser vs various Node versions:
+    'connection',
+
     // Varies on OS config:
     'accept-language',
 
@@ -69,7 +72,6 @@ describe("Request initiated subscriptions", () => {
 
             const matchableHeaders = _.omit(seenRequest.headers, INCONSISTENT_HEADERS);
             expect(matchableHeaders).to.deep.equal({
-                'connection': isNode ? 'close' : 'keep-alive',
                 'accept': '*/*',
                 'content-length': '9',
                 'content-type': 'text/plain;charset=UTF-8',
@@ -166,7 +168,6 @@ describe("Request initiated subscriptions", () => {
 
             const matchableHeaders = _.omit(seenRequest.headers, INCONSISTENT_HEADERS);
             expect(matchableHeaders).to.deep.equal({
-                'connection': isNode ? 'close' : 'keep-alive',
                 'accept': '*/*',
                 'content-length': '9',
                 'content-type': 'text/plain;charset=UTF-8',