[PRISM] Enable passing tests for index expressions

test/.excludes-prism/TestCall.rb

@@ -1,3 +0,0 @@
-exclude(:test_call_op_asgn_keywords, "https://github.com/ruby/prism/issues/2438")
-exclude(:test_call_op_asgn_keywords_mutable, "https://github.com/ruby/prism/issues/2438")
-exclude(:test_kwsplat_block_order_op_asgn, "https://github.com/ruby/prism/issues/2438")

test/.excludes-prism/TestParse.rb

@@ -2,7 +2,6 @@ exclude(:test_error_def_in_argument, "unknown")
 exclude(:test_global_variable, "unknown")
 exclude(:test_invalid_char, "unknown")
 exclude(:test_location_of_invalid_token, "unknown")
-exclude(:test_op_asgn1_with_block, "unknown")
 exclude(:test_percent, "unknown")
 exclude(:test_question, "unknown")
 exclude(:test_shareable_constant_value_ignored, "unknown")