Create 26 track

[rvagg]

We're not there yet, but I'm making this issue in preparation and because I have 26 already approved by snapcraft.

1. Request a new Track for the "node" Snap in the Snapcraft forum in the "Store requests" section. The track should be the major release line number (e.g. 14). The "node" Snap has fast-track approval and is usually authorized within 24 hours by the administrators. This step needs to be performed in order to upload to a new track. An example of this for 14 can be seen here: https://forum.snapcraft.io/t/track-request-for-node-14-fast-track-please/16842/3
2. Create a new branch in this repository, named nodeXX where XX is the release line number.
3. Edit snapcraft.yaml.sh if required for system configuration required to build the new version. In most cases this is not necessary and the main version can be copied. Where the compiler minimums change, the equivalent changes may need to be made in the script.
4. Edit .github/workflows/cron.yml to add the new release line to the matrix.
5. Start a build (manually, or wait for the GitHub Action to trigger by cron), which will update the snapcraft.yaml file for that branch correctly and push the new branch to https://code.launchpad.net/node-snap where it can be further configured.
6. Navigate to https://code.launchpad.net/node-snap and into the new branch and click on "Create snap package".

• The "name" should be the same as the branch
• The "series" should be inferred from snapcraft.yaml
• The "processors" should be at least: armhf, arm64, amd64, i386, ppc64el, s390x
• "Automatically build when branch changes" should be ticked.
• "Automatically upload to store" should be ticked
• "Registered store package name" should be "node"
• "Risk" should be "stable" (this is "edge" for nightly builds)
• "Track" should be the major release line
• Clicking "Create snap package" should create the workflow and authenticate the publishing with the Snap store (this is a simple multi-step authorization process).

7. Manually request new builds for the Snap from the Snap configuration page in Launchpad ("Request builds").