v0.273.0

What's Changed

• Add mage target for custom backend builds by @wbrowne in #1267

Full Changelog: v0.272.0...v0.273.0

Compatibility

gorelease -base=v0.272.0 -version=v0.273.0
# github.com/grafana/grafana-plugin-sdk-go/build
## compatible changes
Build.Custom: added

# summary
v0.273.0 is a valid semantic version for this release.