Remove single-quote as allowed type URL character from text-format spec.

Revise the recent addition to the spec to allow more characters in type URLs. It has turned out to complicated to support single-quotes since the single-quote in text protos is reserved for string literals.

PiperOrigin-RevId: 842695507

Author: protobuf-github-bot

content/reference/protobuf/textformat-spec.md

@@ -103,7 +103,7 @@ A limited set of URL characters following
 
 ```
 url_unreserved  = letter | dec | "-" | "." | "~" | "_"
-url_sub_delim   = "!" | "$" | "&" | "'" | "(" | ")"
+url_sub_delim   = "!" | "$" | "&" | "(" | ")"
                 | "*" | "+" | "," | ";" | "="
 url_pct_encoded = "%" hex hex
 url_char        = url_unreserved | url_sub_delim | url_pct_encoded