Fix the Pip download URL.

Update CodeQL bundle to 20210304 / CLI 2.4.4

This reverts commit 2f4f48f.

Check if this mitigates the go 1.16 issue

Don't run update release branch workflow on forks.

…r-versions

Update supported GitHub Enterprise Server versions.

Increase the default amount of RAM reserved for the OS

Set externalRepoAuth

Also look for the CodeQL bundle at the custom GitHub AE endpoint.

Remove --external-repository-token option from runner

Mitigation for OOM errors (137/SIGKILL) seen by users when we overcommit the available memory.
For Unix, reserve 1GB.
For Windows, reserve 1.5GB, as the OS needs more memory and estimates inaccurately.

Specifying a token as a cli input leads to a potential for leaking the
token on CI logs. This commit removes the option. Instead, users
should specify a single GitHub token through `--github-auth-stdin` or
by setting the `GITHUB_TOKEN` environment variable. This token should be
created with enough privileges to access the required repository.

This commit adds two new ways of specifying GitHub auth:

1. from the GITHUB_TOKEN environment variable
2. from standard input

This commit does not include any documentation changes and the
descriptions of new command line options will need to be tweaked.

Lock bundler version to 2.2.9.

Allow overriding path of temporary files.

Add detection for GitHub AE.