Warning icon flickers while changing the json schema setting

[sandy081]

Testing #62087

• Configure an invalid schema URL for a json file

"json.schemas": [
		{
			"fileMatch": [
				"vscode/sample.json"
			],
			"url": "https://path/to/schema.json",
		},
	]

• Open sample.json and see warning icon in the status bar
• Open settings which will remove the warning.
• Now change the file name to sampl.json
• Warning is not shown - good
• Change the file name back to sample.json and save
• 🐛 Warning icon appears for a moment

[aeschli]

FYI @xxyy... We tested your PR in this weeks test pass. Of course, fixes are welcome, as always. I'm out the coming month, but @octref can help getting them pushed.