Mk/Scripts/cargo-crates-git-configure.awk: Generate the patch.crates-io section after parsing all the Cargo.toml files

If we have multiple Cargo.toml files with the same crates in the
[patch.crates-io] section we will end up with crates defined mutiple
times and cargo will refuse to proceed.
Write this section after parsing all the Cargo.toml files.

PR: 273280
Reviewed by: tobik

(cherry picked from commit 8fae936cf5a65db050d6b0950a912a4f028e34d8)