Remove code that tries to handle ANSI escape inputs

Syntax highlighting is broken when input contains ANSI escape characters
anyway, so there is not much point in trying to handle ANSI escapes in
input.

tests/integration_tests.rs

@@ -1419,25 +1419,6 @@ fn ansi_highlight_underline() {
         .stderr("");
 }
 
-// Ensure that ANSI passthrough is emitted properly for both wrapping and non-wrapping printer.
-#[test]
-fn ansi_passthrough_emit() {
-    for wrapping in &["never", "character"] {
-        bat()
-            .arg("--paging=never")
-            .arg("--color=never")
-            .arg("--terminal-width=80")
-            .arg(format!("--wrap={}", wrapping))
-            .arg("--decorations=always")
-            .arg("--style=plain")
-            .write_stdin("\x1B[33mColor\nColor \x1B[m\nPlain\n")
-            .assert()
-            .success()
-            .stdout("\x1B[33m\x1B[33mColor\n\x1B[33mColor \x1B[m\nPlain\n")
-            .stderr("");
-    }
-}
-
 #[test]
 fn ignored_suffix_arg() {
     bat()