fix: unreachable DbPool match arm for workspace feature unification

crates/mcp/src/main.rs

@@ -129,7 +129,6 @@ fn wire_repositories(pool: &DbPool) -> anyhow::Result<WireOutput> {
                 library_query: w.library_query,
             })
         }
-        #[cfg(not(any(feature = "sqlite", feature = "postgres")))]
         _ => anyhow::bail!("database backend not compiled into this binary"),
     }
 }