Building container images in forked repositories fails

[TrevorBenson]

Describe the bug
The CNCLI Installer uses the G_ACCOUNT variable. The error was originally found by @Fuma419 when working on #1747, and proposed changing it back to cardano-community. Initially I suggested it be left as G_ACCOUNT and cncli be forked along with guild-operators for consistency in using G_ACCOUNT. However the forked cncli repository does not have any releases from the upstream repo which still leads to failures when installing CNCLI.

#18 6.268   Downloading CNCLI...
#18 6.452 jq: error (at <stdin>:4): Cannot iterate over null (null)
#18 6.460 curl: no URL specified!
#18 6.460 curl: try 'curl --help' or 'curl --manual' for more information
#18 6.461 ERROR: Download of latest release of CNCLI from GitHub failed! Please retry or install it manually.

Checking the forked repository latest release results in:

{
  "message": "Not Found",
  "documentation_url": "https://docs.github.com/rest/releases/releases#get-the-latest-release"
}

To Reproduce
Steps to reproduce the behavior:

1. Fork guild-operators and cncli
2. Go into actions
3. Build the container for testing
4. Observe jq and curl errors above.

Expected behavior
Building in a fork should be possible and lead to a working container image.

Additional context
Should be reproducable from any fork while guild-deploy.sh uses G_ACCOUNT for CNCLI installation steps.

[TrevorBenson]

Link to PR was missing prior to merge, but fixed in #1754 so closing.