[Druid] Use a different repository to download sigar artifacts

[imjalpreet]

The old repository(repository.jboss.org) has been throwing 500 Internal Server Errors.

[ERROR] Failed to execute goal on project presto-druid: Could not resolve dependencies for project com.facebook.presto:presto-druid:presto-plugin:0.282-SNAPSHOT: Failed to collect dependencies at org.apache.druid:druid-processing:jar:0.19.0 -> org.apache.druid:druid-core:jar:0.19.0 -> org.hyperic:sigar:jar:1.6.5.132: Failed to read artifact descriptor for org.hyperic:sigar:jar:1.6.5.132: Could not transfer artifact org.hyperic:sigar:pom:1.6.5.132 from/to sigar (https://repository.jboss.org/nexus/content/repositories/thirdparty-uploads/): transfer failed for https://repository.jboss.org/nexus/content/repositories/thirdparty-uploads/org/hyperic/sigar/1.6.5.132/sigar-1.6.5.132.pom, status: 500 Internal Server Error -> [Help 1]

The new repository has been taken from the recent versions of druid. Since druid-24.0.0, the repository has been changed from https://repository.jboss.org/nexus/content/repositories/thirdparty-uploads/ to https://repository.mulesoft.org/nexus/content/repositories/public (apache/druid#12561)

Test plan
Verified that after this change, we are able to download the sigar artifacts from the new repository and the build succeeds.

If release note is NOT required, use:

== NO RELEASE NOTE ==

[imjalpreet]

@prestodb/committers @tdcmeehan can someone please review this PR? This will unblock the build failures we are seeing in CI pipeline due to one of the repositories being down.