bug #29095 [TwigBridge] require the needed symfony/contracts package (xabbuh)

This PR was merged into the 4.2-dev branch.

Discussion
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[TwigBridge] require the needed symfony/contracts package

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #29086
| License       | MIT
| Doc PR        |

Commits
-------

4400776140 require the needed symfony/contracts package

src/Symfony/Bridge/Twig/composer.json

@@ -17,6 +17,7 @@
     ],
     "require": {
         "php": "^7.1.3",
+        "symfony/contracts": "^1.0",
         "twig/twig": "^1.35|^2.4.4"
     },
     "require-dev": {