Revert "fix: error during deserialization of "INVERTED" index type"

This reverts commit 2ea5939f85.

rust/lancedb/src/index.rs

@@ -120,8 +120,6 @@ pub enum IndexType {
     LabelList,
     // FTS
     FTS,
-    #[serde(alias = "INVERTED")]
-    Inverted,
 }
 
 impl std::fmt::Display for IndexType {
@@ -134,7 +132,6 @@ impl std::fmt::Display for IndexType {
             Self::Bitmap => write!(f, "BITMAP"),
             Self::LabelList => write!(f, "LABEL_LIST"),
             Self::FTS => write!(f, "FTS"),
-            Self::Inverted => write!(f, "FTS"),
         }
     }
 }