fix(akamai): handle non-string user data in base64 decoding

[jessealter]

Proposed Commit Message

fix(akamai): handle non-string user data in base64 decoding

Previously, user data that was base64-encoded was decoded as a string,
causing non-string data (e.g., gzipped user data) to raise an exception.
This change ensures that the output of b64decode is not decoded to a
string, passing along the decoded bytes unchanged.

Additional Context

Test Steps

1. Deploy a Linode instance while supplying user-data that is gzipped and then base64 encoded. You may use any cloudconfig you like or the one provided which will set the hostname to it-worked-gzip, write to /root/proof.txt, and write to the "final_message".

curl -H "Content-Type: application/json" \
     -H "Authorization: Bearer $LINODE_API_TOKEN" \
     -X POST -d '{
       "region": "us-east",
       "type": "g6-nanode-1",
       "image": "linode/ubuntu22.04",
       "label": "cloud-init-test",
       "root_pass": "'"$PASS"'",
       "metadata": {
         "user_data": "H4sIAA759mYAAzWPwQ7CIBBE73zFWK9W71xN/AEPxlNDYEFiCwS2qRo/XrB62cxmX2Zmt3qMs+l1DNY7IbY4E+MWCwc1kfgLCc/9EvOdTO9ePjXwkj0TFKwfSSxtGZosUgA9kuKbxCHHyIdUp93zg+sFqFFMgSXe3xW4UtlVf6z+++Z98kGNmKgU5WqGZcpYi/pQSR2nNBJTEbaBww+U6I7tjzz54PCMc0Yrm8igsowya01kyGw6IT6RMgJw+QAAAA=="
       }
     }' \
     https://api.linode.com/v4/linode/instances

2. You will see an exception is raised in /var/log/cloud-init.log when cloud-init attempts to decode the gzipped user data.

3. Replace the installed cloud-init package with a patched release, or simply patch DataSourceAkamai.py.

4. Run cloud-init clean, followed by cloud-init init.

5. You should observe the cloudconfig being successfully decoded, decompressed, and applied.

Merge type

• Squash merge using "Proposed Commit Message"
• Rebase and merge unique commits. Requires commit messages per-commit each referencing the pull request number (#<PR_NUM>)