fix: replace infinite loops with bounded polling in p2p switch tests (#2800)

## Summary
- Replace unbounded `for` loops in
`TestPeerRemovedFromReactorOnStopWithNilReason` and
`TestSwitchInitPeerIsNotCalledBeforeRemovePeer` with
`require.Eventually` calls that timeout after 5 seconds
- The infinite loops could hang forever if the peer was never added to
the switch, causing the test to hit the 15-minute CI timeout

Closes #2791

## Test plan
- [x] `go test -v -run
"TestSwitchInitPeerIsNotCalledBeforeRemovePeer|TestPeerRemovedFromReactorOnStopWithNilReason"
-count=1 -timeout=30s ./p2p/` passes locally

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: rootulp

p2p/switch_test.go

@@ -823,13 +823,13 @@ func TestSwitchInitPeerIsNotCalledBeforeRemovePeer(t *testing.T) {
 	require.NoError(t, err)
 
 	// wait till the switch adds rp to the peer set, then stop the peer asynchronously
-	for {
-		time.Sleep(20 * time.Millisecond)
+	require.Eventually(t, func() bool {
 		if peer := sw.Peers().Get(rp.ID()); peer != nil {
 			go sw.StopPeerForError(peer, "test", "mockReactor")
-			break
+			return true
 		}
-	}
+		return false
+	}, 5*time.Second, 20*time.Millisecond, "peer was never added to switch")
 
 	// simulate peer reconnecting to us
 	_, err = rp.Dial(sw.NetAddress())
@@ -872,12 +872,10 @@ func TestPeerRemovedFromReactorOnStopWithNilReason(t *testing.T) {
 
 	// wait till the switch adds rp to the peer set
 	var peer Peer
-	for {
-		time.Sleep(20 * time.Millisecond)
-		if peer = sw.Peers().Get(rp.ID()); peer != nil {
-			break
-		}
-	}
+	require.Eventually(t, func() bool {
+		peer = sw.Peers().Get(rp.ID())
+		return peer != nil
+	}, 5*time.Second, 20*time.Millisecond, "peer was never added to switch")
 
 	// verify peer is in reactor's peer set
 	reactorPeerSet := sw.peerSetForReactor(reactor)