Migrate Helm e2e tests to terratest v2 modules

[antoninbas]

Closes #1290, which bumped terratest to v1. This goes further and moves us to the v2 modules instead.

Why

terratest v1 ships as a single Go module, and modules/k8s imported modules/aws for a single EC2 call (resolving EKS node public IPs in GetServiceEndpoint). modules/aws is one flat package covering every AWS service, so importing modules/k8s pulled the whole AWS SDK into our graph:

antrea.io/antrea-ui/test/e2e_helm
github.com/gruntwork-io/terratest/modules/k8s
github.com/gruntwork-io/terratest/modules/aws
github.com/aws/aws-sdk-go-v2/aws

That was 36 aws-sdk-go-v2 entries in go.mod for code we never call.

Upstream fixed this: gruntwork-io/terratest#1877 broke the k8s -> aws edge (node addresses now prefer ExternalIP, so there is no EC2 call and no ec2:DescribeInstances permission needed), and #1881 added CI gating so the edge cannot come back. v2 also splits terratest into 16 per-package modules, so we only pull what we use.

Result

	before	after
aws-sdk-go-v2 entries in go.mod	36	0
go.sum lines	470	375

Changes

• Import paths move to the v2 modules: k8s/v2, helm/v2, http-helper -> httphelper/v2 (the package identifier loses its underscore), and random -> core/v2/random.
• v2 dropped the non-Context function variants, so the helm and k8s calls become their …Context equivalents with an explicit ctx.
• httphelper collapsed the URL and TLS parameters into an HttpGetOptions struct.
• random.UniqueId -> random.UniqueID.
• Pre-existing bug fix: the first two arguments to k8s.NewKubectlOptions were swapped. The signature is NewKubectlOptions(contextName, configPath, namespace), but we passed (kubeconfigPath, kubeconfigContext, ...), so -kubeconfig and -context were wired to the wrong fields. This is not migration fallout — the signature is identical in v1 and v2. It went unnoticed because both flags default to the empty string.

In the t.Cleanup that deletes the OIDC Secret I pass context.Background() rather than t.Context(), because t.Context() is canceled just before Cleanup functions run and the delete would fail. The plain defer blocks inside the subtest still run before the test function returns, so t.Context() is valid there.

Note on the beta

v2.0.0-beta.2 is a pre-release. I think that is acceptable here: terratest is a test-only dependency that never reaches a shipped binary, and the alternative is carrying the AWS SDK until v2 is final. Worth flagging explicitly for review, though — and Renovate will not track these the way it tracked v1.

Testing

go build ./..., go vet ./..., go test -c ./test/e2e_helm/ and golangci-lint all pass locally. The e2e suite itself needs a live cluster, so I have not run it — relying on CI for that.