Revert "Use defined environment variables in the image build process"

This reverts commit 901adf4.
fixes #985 and #931

Signed-off-by: Chris Shucksmith <chris@shucksmith.co.uk>

podman_compose.py

@@ -2408,10 +2408,6 @@ async def build_one(compose, args, cnt):
         build_args.append("--pull-always")
     elif getattr(args, "pull", None):
         build_args.append("--pull")
-    env = dict(cnt.get("environment", {}))
-    for name, value in env.items():
-        build_args += ["--env", f"{name}" if value is None else f"{name}={value}"]
-
     args_list = norm_as_list(build_desc.get("args", {}))
     for build_arg in args_list + args.build_arg:
         build_args.extend((