Doppler mutliline secrets issue test

Create test Doppler project and get service token to add to GitHub:

make doppler-project

Generate a key using the Ed25519 algorithm which produces the "Load key "id_rsa": invalid format" error and create new SSH_KEY secret:

make gen-key

Run the Test SSH key Action and observe that the initial key verification fails but passes once dos2unix is used.

Now set SSH_KEY using the CLI:

make set-key-cli

Rr-run the Test SSH key Action and observe that the initial key verification now passes.