Log 'did not update syntactic tokens' at debug level

These occur commonly when the edit range is empty and don't indicate an
issue.

Author: fwcd

Sources/SourceKitLSP/Swift/SwiftLanguageServer.swift

@@ -191,7 +191,7 @@ public final class SwiftLanguageServer: ToolchainLanguageServer {
           let start: Position = snapshot.positionOf(utf8Offset: offset),
           let end: Position = snapshot.positionOf(utf8Offset: offset + length) else {
       // This e.g. happens in the case of empty edits
-      log("did not update lexical/syntactic tokens, no range found", level: .warning)
+      log("did not update lexical/syntactic tokens, no range found", level: .debug)
       return docTokens
     }