This commit removes gogoproto.enumvalue_customname,
gogoproto.goproto_enum_prefix and gogoproto.enum_customname.
All of them make proto-generated Go code more idiomatic, but we already
don't use these enums in our external-surfacing types and they are anyway
not supported by Google's official toolchain (see #6564).
Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>
Dependencies may be switching to use the new `%w` formatting
option to wrap errors; switching to use `errors.Is()` makes
sure that we are still able to unwrap the error and detect the
underlying cause.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
