ci: update windows image and fix pixman build on android
ci: update windows image
Some root certs expired, which causes problems with letsencrypt
certificates, so update to latest image with updated certificates.
https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/
Fixes #515
ci: disable aarch64 neon asm in pixman to fix android build
To work around build failures, see #515