Steps to replicate the issue (include links if applicable):

• Write a test for a component that contains CdxTextInput
• Have that test set a value in CdxTextInput's internal <input>field, e.g by doing wrapper.get('input').setValue('inputted text'),
• Run that test in Vue compat mode.

What happens?:

• CdxTextInput emits a model update event, but its value is an Event object, rather than the inputted text.

What should have happened instead?:

• The value of the model update event should have been the inputted text.

Software version (skip for WMF-hosted wikis like Wikipedia):

		"@vue/test-utils": "2.0.0-rc.21",
		"@vue/vue3-jest": "27.0.0-alpha.4",
		"@wikimedia/codex": "0.2.1",
		"@vue/compat": "3.2.37",
		"jest": "27.4.7",
		"vue": "3.2.37"

Other information (browser name/version, screenshots, etc.):

• The bug is demonstrated in a minimal example here.
• The bug does not occur if Vue compat mode is not used.