blast_repo fixes (dart-archive/source_span#118)

drop-lint

Author: kevmoo

pkgs/source_span/analysis_options.yaml

@@ -22,7 +22,6 @@ linter:
   - literal_only_boolean_expressions
   - missing_whitespace_between_adjacent_strings
   - no_adjacent_strings_in_list
-  - package_api_docs
   - prefer_const_declarations
   - prefer_expression_function_bodies
   - prefer_final_locals