Auto merge of #9839 - jonhoo:prefer-cargo-toml-patch, r=ehuss

Stabilize patch-in-config (and prefer config over manifest)

Tracking issue: https://github.com/rust-lang/cargo/issues/9269

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This stabilizes the `patch-in-config` feature ([unstable entry](https://doc.rust-lang.org/cargo/reference/unstable.html#patch-in-config)) following the discussion in https://github.com/rust-lang/cargo/issues/9269#issuecomment-904913263.

As requested, this PR _also_ changes the precedence behavior such that a `[patch]` for the same dependency in both `.cargo/config.toml` and `Cargo.toml` prefers the patch from the configuration file over the one from the manifest, which matches the behavior of other overlapping configuration options. The corresponding test has also been updated to reflect this change in behavior.

diff --cc tests/testsuite/patch.rs
Simple merge