support/download: replace deprecated .cargo/config

With the current vendoring process, any Cargo build emits the
following warning:

warning: `.../.cargo/config` is deprecated in favor of `config.toml`

.cargo/config.toml was introduced in 1.39 [1], so there shouldn't be
backwards compatibility issues in Buildroot. However, because the
generated config file becomes part of the vendored archive, this
changes the hashes of all Cargo-based packages.

[1] https://doc.rust-lang.org/cargo/reference/config.html#hierarchical-structure

Signed-off-by: Fiona Klute (WIWA) <fiona.klute@gmx.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Arnout Vandecappelle <arnout@rnout.be>

support/download/cargo-post-process

@@ -31,14 +31,14 @@ post_process_unpack "${base_name}" "${output}"
 # Do the Cargo vendoring
 pushd "${base_name}" > /dev/null
 
-# Create the local .cargo/config with vendor info
+# Create the local .cargo/config.toml with vendor info
 mkdir -p .cargo/
 mkdir -p "${CARGO_HOME}"
 flock "${CARGO_HOME}"/.br-lock \
 cargo vendor \
     --manifest-path "${manifest}" \
     --locked VENDOR \
-    > .cargo/config
+    > .cargo/config.toml
 
 # "cargo vendor' outputs on stderr a message directing to add some data
 # to the project's .cargo/config.toml, data that it outputs on stdout.