fix: Only build for 8.7+PTX on tegra and fix activation variables

[ruben-arts]

Checklist

• Used a personal fork of the feedstock to propose changes
• Bumped the build number (if the version is unchanged)
• [na] Reset the build number to 0 (if the version changed)
• [na] Re-rendered with the latest conda-smithy (Use the phrase @conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [na] Ensured the license file is being packaged.

Based on the coment from @traversaro: #494 (comment)

This will remove the 10.1 CUDA Arch, and only build for 8.7+PTX, meaning it should support all future version from 8.7 onward. But only with jit compilation.

8.7 is the Nvidia Jetson Orin Nano board's arch.

---

#495 Is also merged into this PR to reduce duplicate CI times.

This uses the env_vars.d JSON files instead and write the values properly using a little Python helper script.

Removing the activations scripts and having a cross platform script that's tested on all platforms.

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found some lint.

Here's what I've got...

For recipe/meta.yaml:

• ❌ In conda-forge.yml: $.github_actions = {'resize_win_partitions': True, 'self_hosted': True, 'store_build_artifacts': True, 'timeout_minutes': 1440, 'triggers': ['push', 'pull_request']}.

  {'resize_win_partitions': True, 'self_hosted': True, 'store_build_artifacts': True, 'timeout_minutes': 1440, 'triggers': ['push', 'pull_request']} is not valid under any of the given schemas

  Schema

  {
    "anyOf": [
      {
        "$ref": "#/$defs/GithubActionsConfig"
      },
      {
        "type": "null"
      }
    ]
  }

For recipe/meta.yaml:

• ℹ️ The recipe is not parsable by parser conda-souschef (grayskull). This parser is not currently used by conda-forge, but may be in the future. We are collecting information to see which recipes are compatible with grayskull.
• ℹ️ The recipe is not parsable by parser conda-recipe-manager. The recipe can only be automatically migrated to the new v1 format if it is parseable by conda-recipe-manager.

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