gitHubReleaseAssetURL owner-repo version pattern

gitHubReleaseAssetURL calls the GitHub API to retrieve the latest releases about the given owner-repo, returning structured data as defined by the GitHub Go API bindings. It iterates through all the versions of the release, returning the first entry equal to version. It then iterates through all the release's assets, returning the first one that matches pattern. pattern is a shell pattern as described in path.Match.

Calls to gitHubReleaseAssetURL are cached so calling gitHubReleaseAssetURL with the same owner-repo will only result in one call to the GitHub API.

!!! example

```
{{ gitHubReleaseAssetURL "FiloSottile/age" "age v1.2.0" (printf "age-*-%s-%s.tar.gz" .chezmoi.os .chezmoi.arch) }}
{{ gitHubReleaseAssetURL "twpayne/chezmoi" "v2.50.0" (printf "chezmoi-%s-%s" .chezmoi.os .chezmoi.arch) }}
```