refactor: remove enum variants nothing constructs

ConfigErrorKind::Missing and ::InvalidField and SqlFileRole::Yaml are
never constructed or matched; XSB077 reported them.

Author: kvlonge

crates/sqlbuild-config/src/errors.rs

@@ -9,10 +9,6 @@ pub enum ConfigErrorKind {
     Construct,
     /// The document uses a feature the native reader leaves to Python.
     Unsupported,
-    /// A required file does not exist.
-    Missing,
-    /// A field SQLBuild reads has the wrong type or an invalid value.
-    InvalidField,
 }
 
 /// A configuration failure, at its one-based line and column where known.

crates/sqlbuild-refactor/src/refactoring/models.rs

@@ -51,7 +51,6 @@ pub enum SqlFileRole {
     Hook,
     Function,
     Schema,
-    Yaml,
 }
 
 /// One requested rename or move.