refactor: use envtest sideloading from dev-kit

Makefile

@@ -1,5 +1,5 @@
 # Include ODC common make targets
-DEV_KIT_VERSION := v1.0.15
+DEV_KIT_VERSION := v2.1.0
 -include common.mk
 common.mk:
 	@[ -f .common.mk-download ] || \
@@ -70,11 +70,6 @@ lint: lint-no-golangci golangci-lint ## Run linters
 lint-no-golangci: $(ADDLICENSE) shellcheck  ## Run linters but not golangci-lint to exit early in CI/CD pipeline
 	$(MAKE) addlicense-check license=apache comment='$(LICENSE_COMMENT)' pattern='*\.go'
 
-.PHONY: envtest-binaries-sideload
-envtest-binaries-sideload: $(SETUP_ENVTEST) ## Populate the envtest cache for ENVTEST_K8S_VERSION from upstream K8s/etcd releases when controller-tools hasn't packaged it
-	@SETUP_ENVTEST=$(SETUP_ENVTEST) BIN_DIR=$(LOCALBIN) YQ=$(YQ) \
-		bash hack/envtest-sideload.sh $(ENVTEST_K8S_VERSION)
-
 .PHONY: test
 test: $(SETUP_ENVTEST) $(GINKGO) envtest-binaries-sideload ## Run all tests
 	@KUBEBUILDER_ASSETS="$(shell $(SETUP_ENVTEST) use $(ENVTEST_K8S_VERSION) --bin-dir $(LOCALBIN) -i -p path)" $(GINKGO) -r -cover --fail-fast --require-suite -covermode count --output-dir=$(BUILD_PATH) -coverprofile=arc.full.coverprofile $(testargs)

docs/developer-guide/developing-locally.md

@@ -88,7 +88,7 @@ The system **pins specific tool versions** for reproducibility:
 - Go linter: `v2.5.0`
 - CRD/RBAC generator: `v0.19.0`
 - Kubernetes test API server: `release-0.22`
-- K8s for integration tests: `1.34.1`
+- K8s for integration tests: see `ENVTEST_K8S_VERSION` in the `Makefile`
 
 ***
 
@@ -127,7 +127,7 @@ See Client Libraries section for usage details.
 ARC uses a multi-layered testing strategy:
 
 - **Unit Tests**
-- **Integration Tests** (uses `ENVTEST_K8S_VERSION=1.34.1`)
+- **Integration Tests** (envtest; K8s version pinned by `ENVTEST_K8S_VERSION` in the `Makefile`)
 - **Controller Tests** via envtest
 - **E2E Tests** using local `kind` cluster via `make test-e2e`