add fallback version detection for tarballs < v1.31

[BenTheElder]

ref #3797

This effectively restores the behavior before #3715 only when we can't get the version file, along with a warning. It will not work with pre-release builds or builds with custom version metadata appended, as before, but it will work with normal upstream tagged stable release builds < v1.31.

For 1.31+ we should continue to use the version file, which will work with pre-release builds and builds with custom build metadata (v1.31.1+foo)

Alternative to #3800

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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[BenTheElder]

/hold
This is untested and I'm going to circle back later.

[BenTheElder]

Quickly tested with:

# confirm from this PR
$ kind version
kind v0.26.0-alpha.10+23486f390e6347 go1.22.9 linux/amd64

# build 1.30.0 with a tarball URL
$ kind build node-image https://dl.k8s.io/v1.30.0/kubernetes-server-linux-amd64.tar.gz
Detected build type: "url"
Building using URL: "https://dl.k8s.io/v1.30.0/kubernetes-server-linux-amd64.tar.gz"
Starting to build Kubernetes
Downloading "https://dl.k8s.io/v1.30.0/kubernetes-server-linux-amd64.tar.gz"
WARNING: Using fallback version detection due to missing version file (This command works best with Kubernetes v1.31+)
Finished building Kubernetes
Building node image ...
Building in container: kind-build-1733851560-1979951427
Image "kindest/node:latest" build completed.

# confirm cluster works
$ kind create cluster --name=test --image=kindest/node:latest
Creating cluster "test" ...
 ✓ Ensuring node image (kindest/node:latest) 🖼
 ✓ Preparing nodes 📦  
 ✓ Writing configuration 📜 
 ✓ Starting control-plane 🕹️ 
 ✓ Installing CNI 🔌 
 ✓ Installing StorageClass 💾 
Set kubectl context to "kind-test"
You can now use your cluster with:

kubectl cluster-info --context kind-test

Have a nice day! 👋

$ kubectl version
Client Version: v1.30.6-dispatcher
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: v1.30.0

# cleanup
$ kind delete cluster --name=test
Deleting cluster "test" ...
Deleted nodes: ["test-control-plane"]

# build 1.29.4 from a version
$ kind build node-image v1.29.4
Detected build type: "release"
Building using release "v1.29.4" artifacts
Starting to build Kubernetes
Downloading "https://dl.k8s.io/v1.29.4/kubernetes-server-linux-amd64.tar.gz"
WARNING: Using fallback version detection due to missing version file (This command works best with Kubernetes v1.31+)
Finished building Kubernetes
Building node image ...
Building in container: kind-build-1733852026-2066378617
Image "kindest/node:latest" build completed.

# confirm cluster works
$ kind create cluster --name=test --image=kindest/node:latest
Creating cluster "test" ...
 ✓ Ensuring node image (kindest/node:latest) 🖼
 ✓ Preparing nodes 📦  
 ✓ Writing configuration 📜 
 ✓ Starting control-plane 🕹️ 
 ✓ Installing CNI 🔌 
 ✓ Installing StorageClass 💾 
Set kubectl context to "kind-test"
You can now use your cluster with:

kubectl cluster-info --context kind-test

Have a nice day! 👋

$ kubectl version
Client Version: v1.29.10
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: v1.29.4

$ kind delete cluster --name=test
Deleting cluster "test" ...
Deleted nodes: ["test-control-plane"]

# build with 1.31.0+
$ kind build node-image v1.31.0
Detected build type: "release"
Building using release "v1.31.0" artifacts
Starting to build Kubernetes
Downloading "https://dl.k8s.io/v1.31.0/kubernetes-server-linux-amd64.tar.gz"
Finished building Kubernetes
Building node image ...
Building in container: kind-build-1733852209-1132115696
Image "kindest/node:latest" build completed.

[BenTheElder]

/hold cancel

[stmcginnis]

/lgtm