[BESU-8999] Strange behavior for MiningOptionsTest (#9422)

* [BESU-8999]
Fix issue #8999

* Populated org.hyperledger.besu.util.BesuVersionUtils.VERSION with a default value instead of leaving it null
* Updated regex in tests to spot the new default value for VERSION

Signed-off-by: Gabriele Del Monte <gabriele.delmonte@proton.me>

* [BESU-8999]
Fix issue #8999

* Used null as a default value for version
* Updated regex in tests to match null case

Signed-off-by: Gabriele Del Monte <gabriele.delmonte@proton.me>

* adjust comment

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

---------

Signed-off-by: Gabriele Del Monte <gabriele.delmonte@proton.me>
Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>
Co-authored-by: Sally MacFarlane <macfarla.github@gmail.com>

Author: gabrieledm

app/src/test/java/org/hyperledger/besu/cli/options/MiningOptionsTest.java

@@ -358,7 +358,9 @@ public void pluginBlockTxsSelectionMaxTimeOptionNonPoaNetwork() {
 
   @Test
   public void extraDataDefaultValueIsBesuVersion() {
-    final var expectedRegex = "besu \\d+\\.\\d+(\\.\\d+|\\-develop\\-\\p{XDigit}+)";
+    // Detect also a string with null at the end (case in which metadata are missing because the
+    // JAR is not generated)
+    final var expectedRegex = "besu (\\d+\\.\\d+(\\.\\d+|\\-develop\\-\\p{XDigit}+)|null)";
     internalTestSuccess(
         this::runtimeConfiguration,
         miningParams -> {