fix(debian platform): Re-add conf-files directive for cargo-deb (vectordotdev#18726)

* Revert "fix(debian platform): Remove `conf-files` directive for `cargo-deb` (vectordotdev#18455)"

This reverts commit 40ef7c4.

* Update Cargo.toml

Author: jszwedko

Cargo.toml

@@ -48,6 +48,7 @@ debug = true
 name = "vector"
 section = "admin"
 maintainer-scripts = "distribution/debian/scripts/"
+conf-files = ["/etc/vector/vector.yaml", "/etc/default/vector"]
 assets = [
   ["target/release/vector", "/usr/bin/", "755"],
   ["config/vector.yaml", "/etc/vector/vector.yaml", "644"],