Executable bit set on non-executable files

Our build system noticed some files in this gem that have the executable bit set and shouldn't:

*** WARNING: ./opt/manageiq/manageiq-gemset/gems/snaky_hash-2.0.3/CODE_OF_CONDUCT.md is executable but has no shebang, removing executable bit
*** WARNING: ./opt/manageiq/manageiq-gemset/gems/snaky_hash-2.0.3/CONTRIBUTING.md is executable but has no shebang, removing executable bit
*** WARNING: ./opt/manageiq/manageiq-gemset/gems/snaky_hash-2.0.3/LICENSE.txt is executable but has no shebang, removing executable bit
*** WARNING: ./opt/manageiq/manageiq-gemset/gems/snaky_hash-2.0.3/SECURITY.md is executable but has no shebang, removing executable bit

I was going to submit a PR to remove them, but strangely, the exec bit is not set in the source. However, if you gem install snaky_hash and look at what's shipped, the bit is set. Something in the gem build process is setting the bit, but I couldn't figure it out.