Update heck requirement from 0.4 to 0.5

---
updated-dependencies:
- dependency-name: heck
  dependency-type: direct:production
...

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

Author: dependabot[bot]

postgres-derive/Cargo.toml

@@ -15,4 +15,4 @@ test = false
 syn = "2.0"
 proc-macro2 = "1.0"
 quote = "1.0"
-heck = "0.4"
+heck = "0.5"