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);