Provide an input for github tokens (#172)

* Provide an input for github tokens

- By providing an input for github tokens with a default users no longer have to pass
  the github token via their environment across workflows.
- Remove GITHUB_TOKEN from our environment in all workflows

* Don't run workflows on main on pull requests

Co-authored-by: Paulo F. Oliveira <paulo.ferraz.oliveira@gmail.com>

dist/index.js

@@ -7612,9 +7612,12 @@ async function get(url0, pageIdxs) {
       const headers = {
         'user-agent': 'setup-beam',
       }
-      if (process.env.GITHUB_TOKEN) {
-        headers.authorization = `Bearer ${process.env.GITHUB_TOKEN}`
+      const GithubToken = getInput('github-token', false)
+
+      if (GithubToken) {
+        headers.authorization = `Bearer ${GithubToken}`
       }
+
       if (pageIdx !== null) {
         url.searchParams.append('page', pageIdx)
       }