Remove problematic Kotlin model.

Author: Max Schaefer

java/ql/lib/change-notes/2024-01-31-new-models.md

@@ -10,7 +10,6 @@ category: minorAnalysis
   * java.nio.file
   * java.util.zip
   * javax.servlet
-  * kotlin.io
   * org.apache.commons.io
   * org.apache.hadoop.fs
   * org.apache.hadoop.fs.s3a

java/ql/lib/ext/kotlin.io.model.yml

@@ -3,7 +3,6 @@ extensions:
       pack: codeql/java-all
       extensible: sinkModel
     data:
-      - ["kotlin.io", "FilesKt", False, "appendText$default", "(File,String,Charset,int,Object)", "", "Argument[0]", "path-injection", "ai-manual"]
       - ["kotlin.io", "FilesKt", False, "deleteRecursively", "(File)", "", "Argument[0]", "path-injection", "ai-manual"]
       - ["kotlin.io", "FilesKt", False, "inputStream", "(File)", "", "Argument[0]", "path-injection", "ai-manual"]
       - ["kotlin.io", "FilesKt", False, "readBytes", "(File)", "", "Argument[0]", "path-injection", "ai-manual"]