Tidy up the getsentry/Ben.Demystifier module

[jamescrosswell]

Currently none of the CI checks pass on the main branch of the fork that we're maintaining of Ben.Demystifier. See this fairly trivial PR for example:

• Disable file system analyzer warning Ben.Demystifier#6

We should address this the build issues on CI so that we can use this to run meaningful checks and more easily accept pull requests.