Fixes and improvements for source builds (#51422)
- A GMP patch was malformed; copy the corrected version from Yggdrasil
- Always invoke `patch` with `-f` to avoid interactive prompts during
build
- Don't quote the path to `python`, or nghttp2's configure script fails
with `error: Python interpreter is too old` (but `config.log` reveals
`"/usr/bin/python": No such file or directory`)
