Fix maven minimum version recommended in the readme (powsybl#3742)

Fix maven minimum version recommended in the readme (powsybl#3742)

* Fix maven minimum version recommended in the readme
* Update README.md

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Signed-off-by: CARON Alice <alice.caron@rte-france.com>
Co-authored-by: Nicolas Rol <nicolas.rol@rte-france.com>
Signed-off-by: Thomas Bouquet <thomas.bouquet@rte-france.com>

Author: 2 people

README.md

@@ -46,7 +46,7 @@ https://github.com/powsybl/powsybl-gse page.
 
 Powsybl-core project is fully written in Java, so you only need few requirements:
 - JDK *(21 or greater)*
-- Maven *(3.8.1 or greater, 3.9.x recommended)* - you could use the embedded maven wrapper instead if you prefer (see [Using Maven Wrapper](#using-maven-wrapper))
+- Maven *(3.9.9 or greater)* - you could use the embedded maven wrapper instead if you prefer (see [Using Maven Wrapper](#using-maven-wrapper))
 
 To run all the tests, simply launch the following command from the root of the repository:
 ```