minor symfony#20938 remove reference to Travis CI (no longer free) (tacman)

This PR was submitted for the 7.2 branch but it was merged into the 6.4 branch instead.

Discussion
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remove reference to Travis CI (no longer free)

On a related note, the test matrix is old, referencing Symfony 4.  But I'm not sure of the best way to rework this.

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Commits
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e66bd63 remove reference to Travis CI (no longer free)

Author: javiereguiluz

bundles/best_practices.rst

@@ -195,8 +195,7 @@ Continuous Integration
 
 Testing bundle code continuously, including all its commits and pull requests,
 is a good practice called Continuous Integration. There are several services
-providing this feature for free for open source projects, like `GitHub Actions`_
-and `Travis CI`_.
+providing this feature for free for open source projects, like `GitHub Actions`_.
 
 A bundle should at least test: