Secure code analysis fixes

[dms1981]

This PR does the following:

• Sets appropriate permissions for the documentation workflow
• Catches and fixes a few typographical errors
• Adds an appropriate KMS policy to allow the bastion_linux_ec2_role to only use the KMS key for decryption purposes
• Pins the S3 bucket module to a commit hash

[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, AWS007, AWS002

======================================================
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
  ──────────────────────────────────────────
  disk i/o             256.704µs
  parsing              357.266756ms
  adaptation           738.208µs
  checks               8.768597ms
  total                367.030265ms

  counts
  ──────────────────────────────────────────
  modules downloaded   1
  modules processed    2
  blocks processed     96
  files read           8

  results
  ──────────────────────────────────────────
  passed               16
  ignored              44
  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_AWS_144,CKV_AWS_18
2023-10-16 19:58:11,557 [MainThread  ] [WARNI]  Failed to download module github.com/ministryofjustice/modernisation-platform-terraform-s3-bucket?ref=8688bc15a08fbf5a4f4eef9b7433c5a417df8df1:None (for external modules, the --download-external-modules flag is required)
terraform scan results:

Passed checks: 70, Failed checks: 0, Skipped checks: 0

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