test: add highlighted outputs for Tcl shebang regression tests

Generate highlighted test outputs for tclsh, wish, and expect
shebang detection files to prevent regressions.

tests/syntax-tests/highlighted/Tcl/expect_shebang

@@ -0,0 +1,7 @@
+#!/usr/bin/expect -f
+# Expect script detected via expect shebang
+set timeout 30
+spawn ssh user@host
+expect "password:"
+send "secret\r"
+expect eof