Exclude out symbol encoding mismatch for the moment to re-green ci

Author: enebo

test/mri/excludes/TestM17N.rb

@@ -26,6 +26,7 @@
 exclude :test_string_inspect_encoding, "needs investigation"
 exclude :test_string_mixed_unicode, "needs investigation"
 exclude :test_symbol, "needs investigation"
+exclude :test_symbol_op, "random operators setting encoding earlier"
 exclude :test_union_1_nonascii_string, "needs investigation"
 exclude :test_union_1_regexp, "needs investigation"
 exclude :'test_utf_16_32_codepoints(UTF-16BE)', "needs investigation"