feat: K8S KYAML output format support (#2560)

* feat: K8S KYAML output format support

Reference: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cli/5295-kyaml/README.md
Co-authored-by: Codex <codex@openai.com>
Generated-with: OpenAI Codex CLI (partial)
Signed-off-by: Robin H. Johnson <rjohnson@coreweave.com>

* build: gomodcache/gocache should not be committed

Signed-off-by: Robin H. Johnson <rjohnson@coreweave.com>

* chore: fix spelling of behaviour

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>

* build: pass GOFLAGS to docker to support buildvcs=false

In trying to develop the KYAML support, various tests gave false
positive results because they made assumptions about Git functionality
Make it possible to avoid that by passing GOFLAGS='-buildvcs=false' to
to Makefile.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>

* doc: cover documentScenarios for tests

Signed-off-by: Robin H. Johnson <rjohnson@coreweave.com>

* build: exclude go caches from gosec

Without tuning, gosec scans all of the vendor/gocache/gomodcache, taking
several minutes (3m35 here), whereas the core of the yq takes only 15
seconds to scan.

If we intend to remediate upstream issues in future; add a seperate
target to scan those.

Signed-off-by: Robin H. Johnson <rjohnson@coreweave.com>

---------

Signed-off-by: Robin H. Johnson <rjohnson@coreweave.com>
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Co-authored-by: Codex <codex@openai.com>

.gitignore

@@ -69,3 +69,7 @@ debian/files
 .vscode
 
 yq3
+
+# Golang
+.gomodcache/
+.gocache/