When cross-compiling, "bash" is missing from %build-inputs,
leading to a build error. Use this-package-input instead of
%build-inputs to resolve this. While we're at it, eliminate
all uses of %outputs and %build-inputs.

* gnu/packages/python.scm
  (wrap-python3)[arguments]<#:builder>: Eliminte %outputs
  and %build-inputs.
---
 gnu/packages/python.scm | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)