Soft Lock of editor when canceling a save dialog opened by Focus Lost flow.

### Tested versions

- Reproducible in: v4.2.1.stable.mono.official [b09f793f5]

### System information

Godot v4.2.1.stable.mono - Windows 10.0.22631 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4080 (NVIDIA; 31.0.15.5176) - AMD Ryzen Threadripper 3960X 24-Core Processor (48 Threads)

### Issue description

When the Save On Focus Lost flow has to save an new file it will open the Save as dialog box, if you close that box you soft lock the editor.

### Steps to reproduce

Setup:
Have the Interface -> Editor -> Save on Focus Loss setting set to On

Steps:
1. Open a project
2. Add a new node
3. Click off of the editor to lose focus
4. Click `cancel` on the Save As dialog

Observations:
The editor will no longer accept any input, but it does gain focus. You can see a repeated error in the Output tab when the editor loses focus the next time.

### Minimal reproduction project (MRP)

[SoftLock.zip](https://github.com/godotengine/godot/files/14691712/SoftLock.zip)

The project is empty but does reproduce the error with the given steps.

Start by reproducing the issue with Interface → Editor → Save on Focus Loss enabled, using the provided SoftLock.zip project and the listed steps. Trace the editor's focus-loss save flow and Save As dialog cancellation; done means canceling the dialog no longer soft-locks input and the repeated Output error is absent.

Written by the indexing model from the issue text.