Roles: Add specreduce to Coordinated section

[pllim]

specreduce is listed as Coordinated under https://www.astropy.org/affiliated/index.html#coordinated-package-list but not listed in roles.json. Here, I simply copy over the "Maintainer(s)" listed over there to this JSON file. Whether they are really actively maintaining or not, I do not know. If this listing is no longer accurate, please tell me the current maintainers for specreduce. Thanks!

Affected people in the added listing:

• @tepickering
• @eteq

[eteq]

In practice @kecnry has been doing some maintainer work as well I'd say.

However, @kecnry is not currently a maintainer in any astropy project role, nor @tepickering. perhaps we should first have this be just me in this PR, and then have a spearate PR to add @kecnry and @tepickering following the regular "add people" process? (I made that suggestion just below to facilitate this if you agree, @pllim)

[eteq]

Suggested change

"Tim Pickering",

[pllim]

Just for completeness, Tim is already on https://github.com/orgs/astropy/teams/specreduce-maintainers , so I don't see the problem.

If Kyle should be promoted to this role, please open a separate PR and we can go through the usual procedures for adding people. Thanks!

[hamogu]

I think we can do that "add people" in the same PR and follow the regular process for this PR.