TODO: fix workflow publish-firefox-add-on

[BinToss]

https://github.com/NirmalScaria/le-git-graph/actions/runs/7373480169/job/20062734590

IMPORTANT: web-ext v8 will introduce a new AMO submission API for signing and you might need to take actions when upgrading from v7 to v8. You can test this upcoming change now by specifying --use-submission-api to the sign command. If you want to keep using the API you are using now (via "sign-addon"), you must stay on v7.
Building web extension from /home/runner/work/le-git-graph/le-git-graph
FAIL

WebExtError: The extension could not be signed
at file:///home/runner/work/le-git-graph/le-git-graph/node_modules/web-ext/lib/cmd/sign.js:156:13
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
at async Program.execute (file:///home/runner/work/le-git-graph/le-git-graph/node_modules/web-ext/lib/program.js:268:7)
at async file:///home/runner/work/le-git-graph/le-git-graph/node_modules/web-ext/bin/web-ext.js:13:1