feat(prune): add --use-gitignore flag

[chris-olszewski]

Description

Closes #9789

Adds a flag for opting out of respecting .gitignore. If you want to copy over files that are ignored by git you can now pass --use-gitignore=false to turbo prune.

Testing Instructions

Added unit tests. Quick manual test:

# A gitignored file in the app
[0 olszewski@chriss-mbp] /tmp/turborepo-gitignore-bug $ stat apps/web/.turbo       
16777234 160702923 drwxr-xr-x 6 olszewski wheel 0 192 "Jan 24 14:05:04 2025" "Jan 24 14:05:04 2025" "Jan 24 14:05:04 2025" "Jan 24 14:05:04 2025" 4096 0 0 .turbo
[0 olszewski@chriss-mbp] /tmp/turborepo-gitignore-bug $ turbo_dev --skip-infer prune web --use-gitignore=false
turbo 2.3.4

Generating pruned monorepo for web in /private/tmp/turborepo-gitignore-bug/out
 - Added @repo/eslint-config
 - Added @repo/typescript-config
 - Added @repo/ui
 - Added web
[0 olszewski@chriss-mbp] /tmp/turborepo-gitignore-bug $ stat out/apps/web/.turbo/                
16777234 160756779 drwxr-xr-x 3 olszewski wheel 0 96 "Jan 24 14:07:47 2025" "Jan 24 14:07:30 2025" "Jan 24 14:07:30 2025" "Jan 24 14:07:30 2025" 4096 0 0 out/apps/web/.turbo/
[0 olszewski@chriss-mbp] /tmp/turborepo-gitignore-bug $ rm -r out 
[0 olszewski@chriss-mbp] /tmp/turborepo-gitignore-bug $ turbo_dev --skip-infer prune web --use-gitignore      
turbo 2.3.4

Generating pruned monorepo for web in /private/tmp/turborepo-gitignore-bug/out
 - Added @repo/eslint-config
 - Added @repo/typescript-config
 - Added @repo/ui
 - Added web
[0 olszewski@chriss-mbp] /tmp/turborepo-gitignore-bug $ stat out/apps/web/.turbo/                       
stat: out/apps/web/.turbo/: stat: No such file or directory

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
examples-basic-web	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm
examples-designsystem-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm
examples-gatsby-web	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm
examples-kitchensink-blog	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm
examples-native-web	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm
examples-nonmonorepo	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm
examples-svelte-web	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm
examples-tailwind-web	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm
examples-vite-web	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jan 24, 2025 7:16pm