Update to MAINTAINERS.txt

Couple of suggestions to reflect track leads who stepped down. Otherwise looks right, assigning to @pameeela for the sign-off.

We don't want to release with an out-of-date MAINTAINERS.txt.

I can't see pameeela in any of those changes, just pavlosdan, _doyle_ and mglaman.

The changes have nothing to do with Pam; I just want her sign-off from a governance perspective.

Assigning to Tim for sign-off.

Thanks @phenaproxima!

Merged into 1.x and cherry-picked to 1.0.x.

Automatically closed - issue fixed for 2 weeks with no activity.