App: Remove hardcoded local/src from App and defs.mk

local/src is a janware-specific path, remove it from App and defs.mk.
It's still in pkg.sh as a safety measure. Will have to go, too, but
is kept in for now until further audit.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/App.py

@@ -5,7 +5,6 @@
 from __future__ import annotations
 
 import os
-import pwd
 import re
 import sys
 
@@ -115,6 +114,8 @@ class App(Base):
                 return self.__pretty_topdir
             return self.__topdir
         for d in [self.__projs_root, self.___opt_root]:
+            if d is None:
+                continue
             ret = d + '/' + name
             if os.path.exists(ret):
                 return ret
@@ -353,7 +354,7 @@ class App(Base):
 
         # -- Members with default values
         self.__topdir_fmt = 'absolute'
-        self.__projs_root = pwd.getpwuid(os.getuid()).pw_dir + '/local/src/jw.dev/proj'
+        self.__projs_root: str | None = None
         self.___opt_root = '/opt'
         self.__pretty_projs_root = None
 
@@ -485,7 +486,9 @@ class App(Base):
         return self.__top_name
 
     @property
-    def projs_root(self):
+    def projs_root(self) -> str:
+        if self.__projs_root is None:
+            raise Exception('Tried to get unknown projects root directory')
         return self.__projs_root
 
     @property