Backport of docs: deprecate rsadecrypt into stable-website

[hc-github-team-nomad-core]

Backport

This PR is auto-generated from #18856 to be assessed for backporting due to the inclusion of the label backport/website.

The below text is copied from the body of the original PR.

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rsadecrypt uses PKCS #1 v1.5 padding which has multiple known weaknesses. While it is possible to use safely in Nomad, we should not encourage our users to use bad cryptographic primitives.

If users want to decrypt secrets in jobspecs we should choose a cryptographic primitive designed for that purpose. rsadecrypt was inherited from Terraform which only implemented it to support decrypting Window's passwords on AWS EC2 instances:

hashicorp/terraform#16647

This is not something that should ever be done in a jobspec, therefore there's no reason for Nomad to support this HCL2 function.

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• 9b3c38b

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