Remove desktop-first gl-sm-pt-* utils

What does this MR do?

In !2608 (merged), we have added several responsive CSS utils that follow the desktop-first approach instead of the recommended mobile-first. In an effort to restore our CSS utils library's consistency, this removes invalid gl-sm-pt-* utils.

The approach here is to check whether those utils are being used in our two main projects that rely on @gitlab/ui: GitLab and CustomerDot App. If not usage is found, the util is being removed without further investigation.

Note: We might be affecting other consumers of the package, but we cannot reasonably follow-up on all of them. In any case, we are marking those changes as breaking, meaning that we'll release a new major version when this MR is merged. The changelog entry will recommend migrating to a mobile-first approach wherever those utils where used.

gl-sm-pt-0

GitLab

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-0' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-0' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

CustomersDot App

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-0' app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-0' app/**/*.{js,vue,haml,rb}
# 0 match

gl-sm-pt-1

GitLab

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-1' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-1' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

CustomersDot App

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-1' app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-1' app/**/*.{js,vue,haml,rb}
# 0 match

gl-sm-pt-2

GitLab

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-2' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-2' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

CustomersDot App

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-2' app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-2' app/**/*.{js,vue,haml,rb}
# 0 match

gl-sm-pt-3

GitLab

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-3' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-3' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

CustomersDot App

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-3' app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-3' app/**/*.{js,vue,haml,rb}
# 0 match

gl-sm-pt-4

GitLab

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-4' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-4' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

CustomersDot App

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-4' app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-4' app/**/*.{js,vue,haml,rb}
# 0 match

gl-sm-pt-5

GitLab

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-5' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-5' {ee/,}app/**/*.{js,vue,haml,rb}
# 0 match

CustomersDot App

# Search for direct usages
rg -c --files-with-matches 'gl-sm-pt-5' app/**/*.{js,vue,haml,rb}
# 0 match

# Search for potential interpolated usages
rg -c --files-with-matches '}-pt-5' app/**/*.{js,vue,haml,rb}
# 0 match