🌱 fix: e2e test: validate inputData during log postprocessing to avoid panic

[damdo]

What type of PR is this?

/kind failing-test

What this PR does / why we need it:

validate inputData during log postprocessing to avoid panic.
Occurrence https://prow.k8s.io/view/gs/kubernetes-ci-logs/logs/periodic-cluster-api-provider-aws-e2e/1995405094014685184#1:build-log.txt%3A1594

[PANICKED] in [It] - /usr/local/go/src/runtime/panic.go:792 @ 12/01/25 08:47:22.599
  << Timeline
push_pin
  [PANICKED] Test Panicked
  In [It] at: /usr/local/go/src/runtime/panic.go:792 @ 12/01/25 08:47:22.599
  runtime error: index out of range [1] with length 1
  Full Stack Trace
    panic({0x48b5c60?, 0xc0019e2000?})
    	/usr/local/go/src/runtime/panic.go:792 +0x132
    sigs.k8s.io/cluster-api-provider-aws/v2/test/e2e/shared.postProcessBase64LogData({0xc003156580, 0x6a}, {0x4d195ef?, 0xc000ab8558?}, {0x4d2319d, 0xf})
    	/home/prow/go/src/sigs.k8s.io/cluster-api-provider-aws/test/e2e/shared/common.go:315 +0x3b7
    sigs.k8s.io/cluster-api-provider-aws/v2/test/e2e/shared.DumpMachine({_, _}, _, {{{0xc001fcee90, 0xa}, {0xc00293a840, 0x27}}, {{0xc002b167e0, 0x1f}, {0x0, ...}, ...}, ...}, ...)
    	/home/prow/go/src/sigs.k8s.io/cluster-api-provider-aws/test/e2e/shared/common.go:218 +0x5ac
    sigs.k8s.io/cluster-api-provider-aws/v2/test/e2e/shared.DumpMachines({0x5416508, 0xc0013a2370}, 0xc0004a72c0, 0x0?)
    	/home/prow/go/src/sigs.k8s.io/cluster-api-provider-aws/test/e2e/shared/common.go:127 +0x119
    sigs.k8s.io/cluster-api-provider-aws/v2/test/e2e/shared.AllNodesBeforeSuite.func2()
    	/home/prow/go/src/sigs.k8s.io/cluster-api-provider-aws/test/e2e/shared/suite.go:276 +0x127
    created by sigs.k8s.io/cluster-api-provider-aws/v2/test/e2e/shared.AllNodesBeforeSuite in goroutine 103
    	/home/prow/go/src/sigs.k8s.io/cluster-api-provider-aws/test/e2e/shared/suite.go:267 +0x70c

Release note:

NONE

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign justinsb for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[damdo]

/assign @chrischdi

[chrischdi]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: f07531e0ec6ba89265a0816dae30f066130ff6cc

[damdo]

/assign @kubernetes-sigs/cluster-api-provider-aws-maintainers

[damdo]

/assign @nrb @richardcase @AndiDog @dlipovetsky