Hack windows tests to use rustls to avoid openssl breakage

[clux]

Works around #1191 with a hacky rustls switch on windows only.
This does mean we don't run all-features tests on windows, but that's better than the current (where it crashes early and we don't even know).

Should ideally experiment with getting openssl working, but don't have it in me atm. Just want ci to become green, without turning the thing off completely.

Only functional change here that noticeable outside CI disabling a default TLS stack from kube-client because this is chosen from the facade crate instead.

Few minor CI tweaks while in the area:

• avoid running ci for *.md changes (seems to work but can't avoid plain unit tests atm because they are 'required statuses' for github - and removing that would be awkward)
• remove unwanted codecov status checks (they were introduced by the service as it upgraded..) -- got some of it away

[codecov]

Codecov Report

Merging #1202 (02a8e58) into main (894b508) will decrease coverage by 0.02%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1202      +/-   ##
==========================================
- Coverage   73.52%   73.50%   -0.02%     
==========================================
  Files          68       68              
  Lines        5379     5379              
==========================================
- Hits         3955     3954       -1     
- Misses       1424     1425       +1     

see 1 file with indirect coverage changes

[clux]

alright this garbage is finally working. there's some non-standard sed on the windows workers so the hack is even more brittle than what it was originally.

still, it does make ci green and it technically tests most of windows.

[mateiidavid]

Never an end to openssl and plumbing :( This LGTM although ofc I'm not intimately familiar with the entire pipeline yet.