Make cirrus upload on tag push.

* CI: fix CIRRUS_TAG check when tagging

* CI: cirrus upload on tag+maintenance

* MAINT: Break a long line.

Co-authored-by: Charles Harris <charlesr.harris@gmail.com>

Backport of #22650, #22685, #22690. The travisci builds were failing
for the Python 3.8 builds, so use cirrus instead.

Without any argument towncrier defaults to `build`.  But towncrier
added a `--version` argument to just print the towncrier version.

NumPy relies on passing `--version` which collides.  Even if
towncrier might revert the change, using `towncrier build` explicitly
just doesn't hurt.

Closes gh-18788

Should fix the current failure that "master" does not exist.
I am a bit curious why master does not exist, maybe the CircleCI
git is set up to use some other default.
Move the branch rename to after the commit, to make sure that
the fact that the branch is empty (and `git branch` also)
cannot influence the result.

[ci-skip]

It seems the git in the CircleCI environment does not have the
`--initial-branch` option that my local git has, hopefully
`git branch -m` works fine.

The default of git is still "master", so we need to set
`--initial-branch=main` to ensure that we use the name `main`
that is used in the devdoc repository.

Closes gh-18568

* Upload docs to main branch of neps/devdocs

* Update `master` to `main` to be consistent with current state of renaming

* Remove badges from README

* Replace remaining instances of `master` with `main`

* Add back logo

* Fix CircleCI branch checks

* Fix GA branch name

* master->main in issue templates.

* master->main for 2 links to numpy archive.

* Change master to main in NEP 23

Co-authored-by: Ross Barnowski <rossbar@berkeley.edu>

Signed-off-by: Changqing Li <changqing.li@windriver.com>