Cas Depth Query Param

Fixed Git sources with a depth query parameter

A terraform.source (or stack source) URL carrying the go-getter depth query parameter, such as ...vpc.git?depth=1&ref=v5.21.0, failed to download since v1.1.0, when the CAS became the default path for Git sources. Terragrunt lifted ref out of the URL but left depth in place, so git received ...vpc.git?depth=1 and rejected it as an invalid repository name. A URL with depth and no ref hit the same failure.

Terragrunt now strips depth, with or without a ref, before invoking git, so these sources download again. The clone depth itself always comes from --cas-clone-depth, which defaults to 1; a depth on a source URL is never applied for CAS clones.