Safari support for @counter-style symbols likely to be partial

[foolip]

Only Safari isn't marked as partial implementation here:
https://developer.mozilla.org/en-US/docs/Web/CSS/@counter-style/symbols#browser_compatibility

Often when almost all browsers have a similar note, it actually applies to all browsers because it's some "future" spec concept that nobody has implemented yet. I'm not sure if that's the case, but it would be good to confirm.

Source in BCD:

browser-compat-data/css/at-rules/counter-style.json

Lines 345 to 386 in a2cdb7f

	"symbols": {
	"__compat": {
	"description": "<code>symbols</code>",
	"mdn_url": "https://developer.mozilla.org/docs/Web/CSS/@counter-style/symbols",
	"spec_url": "https://drafts.csswg.org/css-counter-styles/#counter-style-symbols",
	"tags": [
	"web-features:counter-style"
	],
	"support": {
	"chrome": {
	"version_added": "91",
	"partial_implementation": true,
	"notes": "Does not support <code>&lt;image&gt;</code> as a value for the <code>symbols</code> descriptor."
	},
	"chrome_android": "mirror",
	"edge": "mirror",
	"firefox": {
	"version_added": "33",
	"partial_implementation": true,
	"notes": "Does not support <code>&lt;image&gt;</code> as a value for the <code>symbols</code> descriptor."
	},
	"firefox_android": "mirror",
	"ie": {
	"version_added": false
	},
	"oculus": "mirror",
	"opera": "mirror",
	"opera_android": "mirror",
	"safari": {
	"version_added": "17"
	},
	"safari_ios": "mirror",
	"samsunginternet_android": "mirror",
	"webview_android": "mirror"
	},
	"status": {
	"experimental": false,
	"standard_track": true,
	"deprecated": false
	}
	}
	},

The task is to write a test for <image> as a value for the symbols descriptor and see if it really works in Safari. If not, add a similar note as the other browsers.