[3] com_tags, Tagged Items, Remove error-prone structured data markup

[ReLater]

Pull Request for Issue #27358
and additional find with tagged com_banners.category

Testing Instructions

• Create a tag TagA.

• Add this tag to some articles.

• Add intro images to these articles.

• Go to Banners: Categories

• Add tag TagA to a category.

• Create a menu item of type "Tagged Items":
  

• Leave Content Type empty.

• Tabulator Tag Options > Set "Item Image" to "Show"

• Go to https://search.google.com/structured-data/testing-tool
  and test the new menu item/front-end link.

Expected result

• No errors

Actual result

2 errors:

• Error 1 (com_banners.category item): A value for the url field is required.
  Not solvable because a com_banners.category item never has a link/url.
  That's the reason why I removed the (here anyway needless(!)) markup completely instead of solving just error 2.

• Error 2:
  "Duplicate values for itemListElement.url are not allowed."

Reason: Two links inside ItemList marked as "url" (1 around headline, 1 around images).

[ChristineWk]

I have tested this item ✅ successfully on 9ace9e7

---

_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/28010.}

[Quy]

I have tested this item ✅ successfully on 9ace9e7

---

_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/28010.}

[Quy]

RTC

---

_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/28010.}

[HLeithner]

Thanks, if this is needed by a site owner a better override should be possible.