URL-SYNTAX.md: drop link to codepoints.net to pass linkcheck

The link works in a browser, but started failing the `mdlinkcheck` test:
```
check https://codepoints.net/U+00DF
FAIL
docs/URL-SYNTAX.md:199 ERROR links to missing URL https://codepoints.net/U+00DF
```
Ref: https://github.com/curl/curl/actions/runs/16902543407/job/47884625446?pr=18254#step:3:22

Closes #18259

diff --git a/docs/URL-SYNTAX.md b/docs/URL-SYNTAX.md
index 44412b4eb9084bfb4e0dd93cda92efd1776af129..6232e3f609b8efcdc5a3e71f51f4aa10d89643a9 100644 (file)
--- a/docs/URL-SYNTAX.md
+++ b/docs/URL-SYNTAX.md
@@ -195,8 +195,7 @@ When built with libidn2, curl uses the IDNA 2008 standard. This is equivalent
 to the WHATWG URL spec, but differs from certain browsers that use IDNA 2003
 Transitional Processing. The two standards have a huge overlap but differ
 slightly, perhaps most famously in how they deal with the
-[German "double s"](https://en.wikipedia.org/wiki/%c3%9f)
-([LATIN SMALL LETTER SHARP S](https://codepoints.net/U+00DF)).
+[German "double s"](https://en.wikipedia.org/wiki/%c3%9f).
 
 When WinIDN is used, curl uses IDNA 2003 Transitional Processing, like the rest
 of Windows.