Revert "Fix: Nations reject alliance requests during spawn phase" (#3313)

## Description:

Reverts openfrontio/OpenFrontIO#3312


## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

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

w.o.n

src/core/execution/nation/NationAllianceBehavior.ts

@@ -76,11 +76,6 @@ export class NationAllianceBehavior {
     otherPlayer: Player,
     isResponse: boolean,
   ): boolean {
-    // Reject alliance requests during the spawn phase
-    if (this.game.inSpawnPhase()) {
-      return false;
-    }
-
     // Easy (dumb) nations sometimes get confused and accept/reject randomly (Just like dumb humans do)
     if (this.isConfused()) {
       return this.random.chance(2);

tests/NationAllianceBehavior.test.ts

@@ -51,10 +51,6 @@ describe("AllianceBehavior.handleAllianceRequests", () => {
       player,
       new NationEmojiBehavior(random, game, player),
     );
-
-    while (game.inSpawnPhase()) {
-      game.executeNextTick();
-    }
   });
 
   function setupAllianceRequest({
@@ -96,16 +92,6 @@ describe("AllianceBehavior.handleAllianceRequests", () => {
     return mockRequest;
   }
 
-  test("should reject alliance during spawn phase", () => {
-    vi.spyOn(game, "inSpawnPhase").mockReturnValue(true);
-    const request = setupAllianceRequest({});
-
-    allianceBehavior.handleAllianceRequests();
-
-    expect(request.accept).not.toHaveBeenCalled();
-    expect(request.reject).toHaveBeenCalled();
-  });
-
   test("should accept alliance when all conditions are met", () => {
     const request = setupAllianceRequest({});