meta: remove Sam Roberts as maintainer

[sam-github]

I won't have time to be involved in maintaining these, best to remove my name so there are no expectations.

Checklist:

• [ ] Read the Code of Conduct and Contributing Guidelines.

• [ ] Followed the commit message guidelines.

• [ ] Stack adheres to Appsody stack structure.

Modifying an existing stack:

• [ ] Updated the stack version in stack.yaml

Contributing a new stack:

• Describe how application dependencies are managed:

• Explain how Appsody file watcher is utilized:

• Describe other Appsody environment variables defined by the stack image:

• Describe any limitations and known issues:

Related Issues:

[neeraj-laad]

@sam-github Thanks for your help so far on these stacks.

We will need to find new maintainers to keep the linter and stack release process.

[gireeshpunathil]

pls see #828

[neeraj-laad]

closing in favour of #828, #829, #830