Remove POSIX 'cpoptions': '|'

It wasn't even hooked up to anything... must have been removed when
term.c was replaced.

runtime/doc/options.txt

@@ -1964,10 +1964,6 @@ A jump table for the options with a short description can be found at |Q_op|.
 			buffer is modified, unless ! is used.  Vim doesn't
 			need this, since it remembers the full path of an
 			opened file.
-								*cpo-bar*
-		|	The value of the $LINES and $COLUMNS environment
-			variables overrule the terminal size values obtained
-			with system specific functions.
 
 						*'cryptmethod'* *'cm'*
 'cryptmethod'		Removed. |vim-differences| {Nvim}

src/nvim/option_defs.h

@@ -129,7 +129,6 @@
 #define CPO_SPECI       '<'     /* don't recognize <> in mappings */
 #define CPO_REGAPPEND   '>'     /* insert NL when appending to a register */
 /* POSIX flags */
-#define CPO_TSIZE       '|'     /* $LINES and $COLUMNS overrule term size */
 #define CPO_PRESERVE    '&'     /* keep swap file after :preserve */
 #define CPO_SUBPERCENT  '/'     /* % in :s string uses previous one */
 #define CPO_BACKSL      '\\'    /* \ is not special in [] */
@@ -140,7 +139,7 @@
 #define CPO_VIM         "aABceFs"
 #define CPO_VI          "aAbBcCdDeEfFiIJkKlLmMnoOpPqrRsStuvWxXyZ$!%+<>;"
 #define CPO_ALL \
-  "aAbBcCdDeEfFiIJkKlLmMnoOpPqrRsStuvWxXyZ$!%+<>|&/\\.;"
+  "aAbBcCdDeEfFiIJkKlLmMnoOpPqrRsStuvWxXyZ$!%+<>&/\\.;"
 
 /* characters for p_ww option: */
 #define WW_ALL          "bshl<>[],~"