Do not use agent mode for `Edit with Copilot`

[benibenj]

Testing #7715

Edit with Copilot used agent mode which cause a very simple query to take around 3 minutes. The query was "Modify it so that it captures all issues which have the label tree-sticky-scroll". Here is some part of that conversation:

[benibenj]

In your PR I can see that you changed it to ask mode. When I use it, I get Edit mode

[alexr00]

I ended up changing from the "open chat" command to the "new chat" command. For that one, there is not option for ask vs. edit, just "not agent".

[alexr00]

vscode-pull-request-github/src/common/settingsUtils.ts

Lines 171 to 172 in 1ae2612

	// Open chat with the query pre-populated
	await vscode.commands.executeCommand(commands.NEW_CHAT, { inputValue: chatMessage, isPartialQuery: true, agentMode: false });

[alexr00]

Marking as verified per your screenshot.