Bump serde_yaml from 0.9.30 to 0.9.32 in /packer

Bumps [serde_yaml](https://github.com/dtolnay/serde-yaml) from 0.9.30 to 0.9.32.
- [Release notes](https://github.com/dtolnay/serde-yaml/releases)
- [Commits](dtolnay/serde-yaml@0.9.30...0.9.32)

---
updated-dependencies:
- dependency-name: serde_yaml
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

packer/Cargo.toml

@@ -14,7 +14,7 @@ clap = { version = "^3", features = ["derive", "cargo"] }
 shellexpand = "^3"
 tar = "0.4.39"
 serde = { version = "^1", features = ["derive"] }
-serde_yaml = "0.9.30"
+serde_yaml = "0.9.32"
 anyhow = "^1"
 sha2 = "0.10.7"
 data-encoding = "^2"