broken link in release docs (1.0.x) (#1564)

* broken link in release docs

* fix: link to GitHub for Hyperic Sigar (#1552)

sigar seems dormant: the website is not on 'https', and has become
entirely unreachable recently. The repo hasn't seen an update since
9 years.

Perhaps we should consider whether it's responsible to still link to
it at all - but for now let's at least link to the GitHub repo instead
of the defunct website.

---------

Co-authored-by: Arnout Engelen <[email protected]>

Author: pjfanning

docs/src/main/paradox/cluster-metrics.md

@@ -82,7 +82,7 @@ ClusterMetricsExtension.get(system).subscribe(metricsListenerActor);
 
 ## Hyperic Sigar Provisioning
 
-Both user-provided and built-in metrics collectors can optionally use [Hyperic Sigar](http://www.hyperic.com/products/sigar)
+Both user-provided and built-in metrics collectors can optionally use [Hyperic Sigar](https://github.com/hyperic/sigar)
 for a wider and more accurate range of metrics compared to what can be retrieved from ordinary JMX MBeans.
 
 Sigar is using a native o/s library, and requires library provisioning, i.e.

docs/src/main/paradox/release-notes/index.md

@@ -74,7 +74,7 @@ properly acknowledged, please get in touch.
 We haven't had to fix many bugs that were in Akka 2.6.20.
 
 * Optimized JsonFraming breaks existing functionality in v2.6.20 ([PR44](https://github.com/apache/pekko/pull/44))
-* Use random IDs in Async DNS Resolver. This change was made due to [CVE-2023-31442](https://akka.io/security/akka-async-dns-2023-31442.html) in Akka. ([#384](https://github.com/apache/pekko/issues/384))
+* Use random IDs in Async DNS Resolver. This change was made due to [CVE-2023-31442](https://doc.akka.io/reference/security-announcements/akka-async-dns-2023-31442.html) in Akka. ([#384](https://github.com/apache/pekko/issues/384))
 * Include critical TLS fix from Akka 2.6.21 ([#442](https://github.com/apache/pekko/issues/442))
 
 ### Dependency Upgrades