Add UnsupportedVisibleIf check

[stephanie-shopify]

What are you adding in this PR?

Shopify Core is changing so that visible_if on a setting type that doesn't support it is accepted and ignored, instead of failing the file save. The affected types are resource pickers like product and collection, plus color_scheme_group and color_palette. The theme editor always shows those settings. Today ValidSchema reports it as an error, which is how #932 and #963 came up.

• Core: https://meteorite.shopify.io/repos/shop/world/pulls/2172172 (stack: 2172229)
• Schema: Accept visible_if on setting types that ignore it theme-liquid-docs#1922 accepts visible_if on those types, so ValidSchema stops erroring.

This PR:

• Adds UnsupportedVisibleIf and UnsupportedVisibleIfSettingsSchema (severity: warning, recommended). They report visible_if on unsupported types in section, block and local-block schemas and in config/settings_schema.json. Message: visible_if is not supported on settings of type 'product' and will be ignored. The setting is always visible in the theme editor.
• ValidVisibleIf skips those settings, since their expression is never evaluated.
• Shares the type list (VISIBLE_IF_UNSUPPORTED_SETTING_TYPES), which mirrors Core's CONDITIONAL_SETTING_UNSUPPORTED_TYPES.

What's next? Any followup issues?

• shopify.dev docs page for unsupported-visible-if (the check's docs.url points there).
• Merge after the Core stack ships.

Tophatting

{% schema %}
{ "name": "Test", "settings": [
  { "type": "checkbox", "id": "show", "label": "Show" },
  { "type": "product", "id": "p", "label": "Product", "visible_if": "{{ section.settings.show }}" }
] }
{% endschema %}

shopify theme check shows a warning on visible_if (and no ValidSchema error once the theme-liquid-docs PR is live).

Before you deploy

• This PR includes a new checks or changes the configuration of a check
  • I included a minor bump changeset
  • I ran pnpm build and committed the updated configuration files
• [Shopifolk] shopify.dev theme check docs PR
• My feature is backward compatible