Fix Jenkins Git Plugin Errors

I'm currently experiencing issues with the Git plugin on my Jenkins setup. I'm looking for a freelancer skilled in Jenkins, particularly with the latest versions (2.303.2 or newer), who can help resolve error messages that occur during the operation of the Git plugin. Here are the specific details and requirements for this job:

- **Plugin Involved**: Git plugin
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ERROR
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-There were errors checking the update sites: Signature verification failed in update site &#039;default&#039; </div><div><a href='#' class='showDetails'>(show details)</a><pre style='display:none'>java.security.cert.CertificateExpiredException: NotAfter: Thu Jun 01 17:13:16 AEST 2023<br> at java.base/sun.security.x509.CertificateValidity.valid(CertificateValidity.java:277)<br> at java.base/sun.security.x509.X509CertImpl.checkValidity(X509CertImpl.java:675)<br> at java.base/sun.security.provider.certpath.BasicChecker.verifyValidity(BasicChecker.java:190)<br> at java.base/sun.security.provider.certpath.BasicChecker.check(BasicChecker.java:144)<br> at java.base/sun.security.provider.certpath.PKIXMasterCertPathValidator.validate(PKIXMasterCertPathValidator.java:125)<br>Caused: java.security.cert.CertPathValidatorException: validity check failed<br> at java.base/sun.security.provider.certpath.PKIXMasterCertPathValidator.validate(PKIXMasterCertPathValidator.java:135)<br> at java.base/sun.security.provider.certpath.PKIXCertPathValidator.validate(PKIXCertPathValidator.java:224)<br> at java.base/sun.security.provider.certpath.PKIXCertPathValidator.validate(PKIXCertPathValidator.java:144)<br> at java.base/sun.security.provider.certpath.PKIXCertPathValidator.engineValidate(PKIXCertPathValidator.java:83)<br> at java.base/java.security.cert.CertPathValidator.validate(CertPathValidator.java:309)<br> at org.jvnet.hudson.crypto.CertificateUtil.validatePath(CertificateUtil.java:93)<br> at jenkins.util.JSONSignatureValidator.verifySignature(JSONSignatureValidator.java:89)<br> at hudson.model.UpdateSite.verifySignatureInternal(UpdateSite.java:276)<br> at hudson.model.UpdateSite.updateData(UpdateSite.java:239)<br> at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:219)<br> at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:214)<br> at hudson.PluginManager.checkUpdatesServer(PluginManager.java:1951)<br> at hudson.util.Retrier.start(Retrier.java:62)<br> at hudson.PluginManager.doCheckUpdatesServer(PluginManager.java:1922)<br> at jenkins.DailyCheck.execute(DailyCheck.java:93)<br> at hudson.model.AsyncPeriodicWork.lambda$doRun$1(AsyncPeriodicWork.java:102)<br> at java.base/java.lang.Thread.run(Thread.java:829)<br></pre>