bug: nightly builds broken

[rhoerr]

See https://github.com/mage-os/generate-mirror-repo-js/actions/runs/10160780327/job/28097837609#step:8:113

/home/runner/work/generate-mirror-repo-js/generate-mirror-repo-js/src/release-branch-build-tools.js:104
    throw Error(`Unable to determine branch release version for input version "${version}"`)
          ^

Error: Unable to determine branch release version for input version "main"
    at calcNightlyBuildPackageBaseVersion (/home/runner/work/generate-mirror-repo-js/generate-mirror-repo-js/src/release-branch-build-tools.js:[104](https://github.com/mage-os/generate-mirror-repo-js/actions/runs/10160780327/job/28097837609#step:8:105):11)
    at transformVersionsToNightlyBuildVersion (/home/runner/work/generate-mirror-repo-js/generate-mirror-repo-js/src/release-branch-build-tools.js:99:29)
    at /home/runner/work/generate-mirror-repo-js/generate-mirror-repo-js/src/release-branch-build-tools.js:93:20
    at Array.reduce (<anonymous>)
    at transformVersionsToNightlyBuildVersions (/home/runner/work/generate-mirror-repo-js/generate-mirror-repo-js/src/release-branch-build-tools.js:92:43)
    at getPackageVersionsForBuildInstructions (/home/runner/work/generate-mirror-repo-js/generate-mirror-repo-js/src/release-branch-build-tools.js:80:10)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async processBuildInstructions (/home/runner/work/generate-mirror-repo-js/generate-mirror-repo-js/src/release-branch-build-tools.js:179:27)
Error: Process completed with exit code 1.

This appears to be happening because module commerce-data-export has no tags upstream:

Basing https://github.com/mage-os/mirror-commerce-data-export.git package versions on those from reference main
Inspecting Commerce Data Export Packages
Inspecting Commerce Data Export Metapackage

[rhoerr]

The change I made in https://github.com/mage-os/generate-mirror-repo-js/pull/165/files didn't help -- just shifted the error to a different code point. I don't understand the nightly build process well enough yet to know how it previously worked without tags. There are references to fallbackVersion for nightly builds, but the errors happen prior to that code point.

Possibly a regression in https://github.com/mage-os/generate-mirror-repo-js/pull/110 but I haven't pinpointed what/how.

[rhoerr]

It worked once upon a time; was discussed on Discord 2022-10-04: https://discordapp.com/channels/893449664093904936/950670671145467924/1026878893040336938

But frankly I'm not sure if this is worth the effort of fixing. commerce-data-export is a set of Sensei dependency modules that happen to be available to open source but not installed by default. We're not going to get any version or tag data from upstream because it's not a part of the normal Magento Open Source releases.