refactor: Remove all mentions of symmath

docs/guides/conf.py

@@ -22,7 +22,6 @@ sys.path.insert(0, root)
 sys.path.append(root / "docs/guides")
 sys.path.append(root / "common/lib/capa")
 sys.path.append(root / "common/lib/safe_lxml")
-sys.path.append(root / "common/lib/symmath")
 sys.path.append(root / "common/lib/xmodule")
 
 # Use a settings module that allows all LMS and Studio code to be imported
@@ -225,7 +224,6 @@ modules = {
     'cms': 'cms',
     'common/lib/capa/capa': 'common/lib/capa',
     'common/lib/safe_lxml/safe_lxml': 'common/lib/safe_lxml',
-    'common/lib/symmath/symmath': 'common/lib/symmath',
     'common/lib/xmodule/xmodule': 'common/lib/xmodule',
     'lms': 'lms',
     'openedx': 'openedx',

docs/guides/docstrings/common_lib.rst

@@ -10,5 +10,4 @@ out from edx-platform into separate packages at some point.
 
     common/lib/capa/modules
     common/lib/safe_lxml/modules
-    common/lib/symmath/modules
     common/lib/xmodule/modules