blast_repo fixes (dart-lang/source_gen#730)

drop-lint

Author: kevmoo

source_gen/source_gen/analysis_options.yaml

@@ -23,13 +23,11 @@ linter:
     - literal_only_boolean_expressions
     - missing_whitespace_between_adjacent_strings
     - no_runtimeType_toString
-    - package_api_docs
     - prefer_const_declarations
     - prefer_expression_function_bodies
     - prefer_final_locals
     - require_trailing_commas
     - sort_child_properties_last
     - unnecessary_await_in_return
-    - unsafe_html
     - use_full_hex_values_for_flutter_colors
     - use_string_buffers