pkg go/build/constraint, type AndExpr struct, Y Expr
pkg go/build/constraint, type Expr interface, Eval(func(string) bool) bool
pkg go/build/constraint, type Expr interface, String() string
pkg go/build/constraint, type Expr interface, unexported methods
pkg go/build/constraint, type NotExpr struct
pkg go/build/constraint, type NotExpr struct, X Expr
pkg go/build/constraint, type OrExpr struct

- The RuntimeClass scheduler can now simplify steering Linux or Windows pods to appropriate nodes
- All Windows nodes now get the new label `node.kubernetes.io/windows-build` that reflects the Windows major, minor, and build number that are needed to match compatibility between Windows containers and Windows worker nodes.


## Deprecations and Removals

- Kubernetes is now built using go1.15.2
  - build: Update to k/repo-infra@v0.1.1 (supports go1.15.2)
  - build: Use go-runner:buster-v2.0.1 (built using go1.15.1)
  - bazel: Replace --features with Starlark build settings flag
  - hack/lib/util.sh: some bash cleanups
    
    - switched one spot to use kube::logging

- Updated distroless iptables to use released image `registry.k8s.io/build-image/distroless-iptables:v0.2.2`
  - Updated setcap to use released image `registry.k8s.io/build-image/setcap:bullseye-v1.4.2` ([#116509](https://github.com/kubernetes/kubernetes/pull/116509), [@cpanato](https://github.com/cpanato)) [SIG Testing]

        * [Build simple API service with Python FastAPI — Part 1](https://dev.to/cuongld2/build-simple-api-service-with-python-fastapi-part-1-581o) by [cuongld2](https://dev.to/cuongld2).
        * [FastAPI + Zeit.co = 🚀](https://paulsec.github.io/posts/fastapi_plus_zeit_serverless_fu/) by [Paul Sec](https://twitter.com/PaulWebSec).

- Updated distroless I-tables to use registry.k8s.io/build-image/distroless-iptables:v0.2.5 ([#118541](https://github.com/kubernetes/kubernetes/pull/118541), [@jeremyrickard](https://github.com/jeremyrickard)) [SIG Testing]

- Kubectl: The deprecated `kubectl alpha debug` command is removed. Use `kubectl debug` instead. ([#98111](https://github.com/kubernetes/kubernetes/pull/98111), [@pandaamanda](https://github.com/pandaamanda)) [SIG CLI]

- Update build images to Debian 11 (Bullseye)
  - debian-base:bullseye-v1.0.0
  - debian-iptables:bullseye-v1.0.0
  - go-runner:v2.3.1-go1.17.1-bullseye.0
  - kube-cross:v1.23.0-go1.17.1-bullseye.1
  - setcap:bullseye-v1.0.0
  - cluster/images/etcd: Build 3.5.0-2 image

redirection from ci/latest.txt to ci-cross/latest.txt. Users should know exactly where the builds are stored on Google Cloud storage buckets from now on. For example for 1.9 and 1.10, users can specify ci/latest-1.9 and ci/latest-1.10 as the CI build jobs what build images correctly updates those. The CI jobs for master update the ci-cross/latest location, so if you are looking for latest master builds, then the correct parameter to use would be ci-cross/latest. ([#63504](https://github.com/kubernetes...

redirection from ci/latest.txt to ci-cross/latest.txt. Users should know exactly where the builds are stored on Google Cloud storage buckets from now on. For example for 1.9 and 1.10, users can specify ci/latest-1.9 and ci/latest-1.10 as the CI build jobs what build images correctly updates those. The CI jobs for master update the ci-cross/latest location, so if you are looking for latest master builds, then the correct parameter to use would be ci-cross/latest. ([#63504](https://github.com/kubernetes...