chore: bump rust from cef0ec9 to 5218a2b in /dogfood/coder (#20895)

Bumps rust from `cef0ec9` to `5218a2b`.


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dogfood/coder/Dockerfile

@@ -1,5 +1,5 @@
 # 1.86.0
-FROM rust:slim@sha256:cef0ec962e08d8b5dcba05604189e5751c1bd3ec7d12db0a93e4215468d4ac4a AS rust-utils
+FROM rust:slim@sha256:5218a2b4b4cb172f26503ac2b2de8e5ffd629ae1c0d885aff2cbe97fd4d1a409 AS rust-utils
 # Install rust helper programs
 ENV CARGO_INSTALL_ROOT=/tmp/
 # Use more reliable mirrors for Debian packages