Fix various ESLint violations (#402)

## Description:

Fixes a number of ESLint violations. Although I have tested these
changes through the local dev server, I don't have a high confidence
that the testing is sufficient, as I am new to this codebase. This
change would benefit from heightened scrutiny.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

fake.neo

---------

Co-authored-by: Scott Anderson <662325+scottanderson@users.noreply.github.com>

src/client/Main.ts

@@ -84,7 +84,7 @@ class Client {
       "google-ad",
     ) as NodeListOf<GoogleAdElement>;
 
-    window.addEventListener("beforeunload", (event) => {
+    window.addEventListener("beforeunload", () => {
       consolex.log("Browser is closing");
       if (this.gameStop != null) {
         this.gameStop();
@@ -213,7 +213,7 @@ class Client {
     );
   }
 
-  private async handleLeaveLobby(event: CustomEvent) {
+  private async handleLeaveLobby(/* event: CustomEvent */) {
     if (this.gameStop == null) {
       return;
     }