Strictly-confined snaps cannot access hidden directories in the project.

[lengau]

When using the shellcheck snap, it cannot find files under hidden directories. For example, in imagecraft, running make lint-shellcheck errors out with:

docs/.sphinx/metrics/source_metrics.sh: docs/.sphinx/metrics/source_metrics.sh: openBinaryFile: does not exist (No such file or directory)

[jonathan-conder]

Is this relative to /project? If so it probably can't access any directories, not just hidden ones