Change dev_build script for rewritten tool

Signed-off-by: Ivan Velickovic <[email protected]>

dev_build.py

@@ -50,12 +50,6 @@ def main():
         default=False,
         help="Build the example from the SDK build rather than directly from source directory",
     )
-    parser.add_argument(
-        "--tool-from-sdk",
-        action="store_true",
-        default=False,
-        help="Build the using the tool from the SDK rather than directly from the Python source",
-    )
     parser.add_argument(
         "--board",
         help="Target board",
@@ -96,10 +90,6 @@ def main():
         else f"{CWD.absolute()}/example/{args.board}/{args.example}"
     )
 
-    if not args.tool_from_sdk:
-        make_env["PYTHONPATH"] = str(CWD / "tool")
-        make_env["MICROKIT_TOOL"] = f"{executable} -m microkit"
-
     cmd = ["make", "-C", makefile_directory]
 
     run(cmd, env=make_env)