Minor bug on output dir restriction for buildstock_eagle

[lixiliu]

Describe the bug
When running bsb on Eagle, the check on output_directory should include the absolute path too.

buildstockbatch.exc.ValidationError: output_directory must be in /scratch or /projects, output_directory = /lustre/eaglefs/scratch/lliu2/resstock/project_national/national_baseline

To Reproduce
Clone resstock repo to scratch and run sampling on project_national/national_baseline.yml.

Expected behavior
bsb should be able to register that output dir is in fact in scratch since the cloned resstock repo is in scratch

Platform (please complete the following information):

• Simulation platform: Eagle
• BuildStockBatch version, branch, or sha: buildstock-2023.06.0
• resstock or comstock repo version, branch, or sha: any