minor #2883 [Docs] Correct typo in Swup README.md (Kocal)

This PR was merged into the 2.x branch.

Discussion
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[Docs] Correct typo in Swup README.md

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| Docs?         | no <!-- required for new features -->
| Issues        | Fix #... <!-- prefix each issue number with "Fix #", no need to create an issue if none exist, explain below instead -->
| License       | MIT

Commits
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8a72820 [Docs] Correct typo in Swup README.md

Author: Kocal

src/Swup/README.md

@@ -3,7 +3,6 @@
 > [!WARNING]
 > **Deprecated**: This package has been **deprecated** in 2.x and will be removed in the next major version.
 
-We
 To keep the same functionality in your Symfony application, follow these migration steps:
 
 1. Install the `swup` library and its plugins: