example: remove duplicate items in .dockerignore (#91079)
Removed duplicate entries for cache and temporary directories.
```diff
- # Cache directories and temporary data
- .cache/
- .parcel-cache/
- .eslintcache
- .stylelintcache
- .turbo/
- .tmp/
# Cache directories and temporary data
.cache/
.parcel-cache/
.eslintcache
.stylelintcache
.swc/
.turbo/
.tmp/
.temp/
```
Co-authored-by: Joseph <joseph.chamochumbi@vercel.com>
