Build strategy for retrieving repository metadata

[SensibleWood]

User Story

As a system owner I want to ensure that metadata is retrieved judiciously and is not wasteful of machine time or resources.

Detailed Requirement

The majority of repositories referenced in the build will change very slowly (if they change at all). Using a "one-in, all-in" full build approach is therefore inappropriate. A more granular approach is required.

The following is suggested:

• Daily: Update the repository metadata for each repository held in docs/tools.yaml.
• Weekly: Run the source & merge process to pull in new sources and update the repository metadata.

There is also a fair amount of "noise" in the data. For example:

• There are many boilerplate repositories that have not changed since they were created and appear abandoned. An "ignore" rule should be implemented for these repositories.
• Any repositories that return a 403 could be ignored from subsequent runs.

The existing full build therefore needs to be split out as above and then reflected in the GitHub Actions config.

[philsturgeon]

I believe GitHub will spit out redirects on rename, which could be followed and updated to avoid things breaking when those redirects eventually stop working.

[SensibleWood]

Build schedule now implemented. New issue will be opened if tweaks to the schedule are required as we collect more data.