Drag-n-drop file to sql editor tool don't clear previous content before adding the new content in windows

[lkmatsumura]

Please note that security bugs or issues should be reported to security@pgadmin.org.

Describe the bug

When drag a file from windows explorer and drop in the query tool the content of the file is merged with
the previous content in the query tool

To Reproduce

Steps to reproduce the behavior:

1. Connect to a database and open the query tool
2. Drag and drop some script file from windows explorer
3. Drag and drop another script file from windows explorer

The new content is mixed with the old in the query tool

Expected behavior

The content be all replaced by the content of the new file dropped

Desktop (please complete the following information):
Client:

• OS: Windows 11
• Browser : Edge, chrome

Server:

• pgAdmin version: 9.17
• Mode: Server Mode
• Package type: RPM (server: Rocky Linux 10.2)