add Django 6 support and simpleTag

queries/highlights.scm

@@ -51,6 +51,7 @@ tag: [
     ("endblock")
     ("comment")
     ("endcomment")
+    ("csp_nonce_attr")
     ("csrf_token")
     ("cycle")
     ("debug")
@@ -105,6 +106,7 @@ tag: [
         ("divisibleby:")
         ("escape")
         ("escapejs")
+        ("escapeseq")
         ("filesizeformat")
         ("first")
         ("floatformat")
@@ -117,7 +119,6 @@ tag: [
         ("json_script:")
         ("last")
         ("length")
-        ("length_is:")
         ("linebreaks")
         ("linebreaksbr")
         ("linenumbers")