minor #10860 Redraw some illustrations as SVG images (javiereguiluz)

This PR was merged into the 4.1 branch.

Discussion
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Redraw some illustrations as SVG images

Now that the problem with SVG images in docs seems to be solved, we can finish updating the rest of images. This PR updates 3 of them.

Commits
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2c45f59 Redraw some illustrations as SVG images

Author: javiereguiluz

_images/components/messenger/overview.png

@@ -31,7 +31,9 @@ Alternatively, you can clone the `<https://github.com/symfony/messenger>`_ repos
 Concepts
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-.. image:: /_images/components/messenger/overview.png
+.. raw:: html
+
+    <object data="../_images/components/messenger/overview.svg" type="image/svg+xml"></object>
 
 **Sender**:
    Responsible for serializing and sending messages to *something*. This