### Bug Description The fallback remote-build behavior gives a misleading error for core22 snaps. It complains about the wrong part name failing validation. ### To Reproduce ``` snapcraft remote-build ``` ### Environment n/a ### snapcraft.yaml ```shell name: checkbox-mir summary: Checkbox tests for the Mir project description: | Collection of tests to be run on devices that are part of the mir project version: git confinement: strict grade: stable base: core22 parts: checkbox-provider-mir: plugin: nil mir_demo_server: plugin: nil ``` ### Relevant log output ```shell snapcraft remote-build is experimental and is subject to change - use with caution. All data sent to remote builders will be publicly available. Are you sure you want to continue? [y/N]: y Issues while validating snapcraft.yaml: The 'parts' property does not match the required schema: 'checkbox-provider-mir' is not a valid part name. Part names consist of lower-case alphanumeric characters, hyphens and plus signs. As a special case, 'plugins' is also not a valid part name. ``` ### Additional context source: https://chat.charmhub.io/charmhub/pl/ytut7oi78id35yoa5zi4xixwta