Remove PREAMBLE_ADDITIONS and MODULE_ADDITIONS

It looks like support for PREAMBLE_ADDITIONS was removed
in #5739 and MODULE_ADDITIONS in #5773.

Author: sbc100

src/shell.js

@@ -400,5 +400,3 @@ assert(ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER || ENVIRONMENT_IS_NODE, 'Pthr
 #endif // ASSERTIONS
 
 {{BODY}}
-
-// {{MODULE_ADDITIONS}}

src/shell_minimal.js

@@ -154,5 +154,3 @@ var currentScriptUrl = typeof _scriptDir !== 'undefined' ? _scriptDir : ((typeof
 #endif // USE_PTHREADS
 
 {{BODY}}
-
-// {{MODULE_ADDITIONS}}

src/support.js

@@ -4,8 +4,6 @@
  * SPDX-License-Identifier: MIT
  */
 
-// {{PREAMBLE_ADDITIONS}}
-
 var STACK_ALIGN = {{{ STACK_ALIGN }}};
 
 {{{ alignMemory }}}