Remove proto comments

They've been made obsolete by .stub.php files and are often
outdated as they're not the source of truth.

Author: MaxSem

CODING_STANDARDS.md

@@ -280,8 +280,7 @@ along with a brief one-line description of what the function does. It would look
 like this:
 
 ```c
-/* {{{ proto int abs(int number)
-   Returns the absolute value of the number */
+/* {{{ Returns the absolute value of the number */
 PHP_FUNCTION(abs)
 {
     ...
@@ -303,8 +302,7 @@ messing up the function summary.
 Optional arguments are written like this:
 
 ```c
-/* {{{ proto object imap_header(int stream_id, int msg_no [, int from_length [, int subject_length [, string default_host]]])
-   Returns a header object with the defined parameters */
+/* {{{ Returns a header object with the defined parameters */
 ```
 
 And yes, please keep the prototype on a single line, even if that line is