DSOS-2590: allow healthcheck protocol specify and remove unused variable

[drobinson-moj]

This change is a fix to the LB target groups - allows healthcheck protocol to be specified. This currently defaults to http but sometimes https is required.
Also removed an unused variable.

I've done a sweep of environments repo and this is only used by DSO and delius-iaps,, and delius doesn't use this functionality, so won't be impacting to anybody else.

Tested in DSO applications against this branch

[github-actions]

TFSEC Scan Success

Show Output

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TFSEC will check the following folders:
.

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Running TFSEC in .
Excluding the following checks: AWS089, AWS099, AWS009, AWS097, AWS018

======================================================
tfsec is joining the Trivy family

tfsec will continue to remain available 
for the time being, although our engineering 
attention will be directed at Trivy going forward.

You can read more here: 
https://github.com/aquasecurity/tfsec/discussions/1994
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  timings
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  disk i/o             140.742µs
  parsing              18.964979ms
  adaptation           218.317µs
  checks               3.421264ms
  total                22.745302ms

  counts
  ──────────────────────────────────────────
  modules downloaded   0
  modules processed    1
  blocks processed     54
  files read           6

  results
  ──────────────────────────────────────────
  passed               3
  ignored              1
  critical             0
  high                 0
  medium               0
  low                  0


No problems detected!

tfsec_exitcode=0

Checkov Scan Success

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Checkov will check the following folders:
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Running Checkov in .
Excluding the following checks: CKV_GIT_1
terraform scan results:

Passed checks: 66, Failed checks: 0, Skipped checks: 13

github_actions scan results:

Passed checks: 176, Failed checks: 0, Skipped checks: 0


checkov_exitcode=0

CTFLint Scan Success

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Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.2.1)
tflint will check the following folders:
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Running tflint in .
tflint_exitcode=0

[Khatraf]

LGTM