Trac #27670: package install can print confusing error messages

For example, while installing the kash3 package, the output includes the
following lines:

{{{
usage: sage-spkg-uninstall [-h] [-v] [-k] spkg [sage_local]
sage-spkg-uninstall: error: argument spkg: invalid spkg_type value:
'kash3'
}}}

This is due to the uninstall script throwing incorrect error types.
After applying this ticket's patch, the output reads:

{{{
usage: sage-spkg-uninstall [-h] [-v] [-k] spkg [sage_local]
sage-spkg-uninstall: error: argument spkg: 'kash3' is not a known spkg
}}}

Which is at least more sensible.  `kash3` is not known because it is an
old-style package that didn't create a directory in `build/pkgs`.

URL: https://trac.sagemath.org/27670
Reported by: gh-BrentBaccala
Ticket author(s): Brent Baccala
Reviewer(s): Erik Bray

build/sage_bootstrap/uninstall.py

@@ -252,7 +252,7 @@ def dir_type(path):
     """
 
     if path and not pth.isdir(path):
-        raise argparse.ArgumentError(
+        raise argparse.ArgumentTypeError(
             "'{0}' is not a directory".format(path))
 
     return path
@@ -267,7 +267,7 @@ def spkg_type(pkg):
     pkgbase = pth.join(PKGS, pkg)
 
     if not pth.isdir(pkgbase):
-        raise argparse.ArgumentError(
+        raise argparse.ArgumentTypeError(
                 "'{0}' is not a known spkg".format(pkg))
 
     return pkg