Announce .NET 9 support

Also add a clarifying statement about "compatible with" vs. "supported" regarding unsupported/EOL-ed versions of .NET Core/.NET

Author: nr-ahemsath

src/content/docs/apm/agents/net-agent/getting-started/net-agent-compatibility-requirements.mdx

@@ -50,7 +50,11 @@ Want to try out our .NET agent? [Create a New Relic account](https://newrelic.co
             title=".NET Core version"
         >
 
-            The .NET agent supports .NET Core version 3.1, and .NET 5.0, 6.0, and 8.0.
+            The .NET agent is compatible with .NET Core version 3.1, and .NET 5.0, 6.0, 7.0, 8.0, and 9.0.
+
+            <Callout variant="important">
+            The agent is only fully supported when instrumenting applications that target [.NET runtimes currently supported by Microsoft](https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-core). The agent is likely to work with the unsupported runtimes listed below, but we do not test new versions of the agent with unsupported runtimes.
+            </Callout>
 
             <table style={{ width: "500px" }}>
             <thead>
@@ -111,6 +115,14 @@ Want to try out our .NET agent? [Create a New Relic account](https://newrelic.co
                     10.0.0 and higher
                 </td>
                 </tr>
+                <tr>
+                <td>
+                    .NET 9.0
+                </td>
+                <td>
+                    10.0.0 and higher
+                </td>
+                </tr>
             </tbody>
             </table>
 
@@ -292,7 +304,7 @@ Want to try out our .NET agent? [Create a New Relic account](https://newrelic.co
             id="target-framework-core"
             title="Target framework version"
         >
-            The .NET agent only supports applications targeting .NET Core 3.1, and .NET 5.0, 6.0, and 8.0. You can find the target framework in your `.csproj` file. Agent compatibility varies across different versions of .NET Core.
+            The .NET agent is compatible with applications targeting .NET Core 3.1, and .NET 5.0, 6.0, 7.0, 8.0, and 9.0. You can find the target framework in your `.csproj` file. Agent compatibility varies across different versions of .NET Core.
 
             Supported:
 
@@ -316,16 +328,14 @@ Want to try out our .NET agent? [Create a New Relic account](https://newrelic.co
             <TargetFramework>net8.0</TargetFramework>
             ```
 
+            ```xml
+            <TargetFramework>net9.0</TargetFramework>
+            ```
+
             <Callout variant="important">
             On Linux ARM64 platforms, the .NET agent <DNT>**only**</DNT> supports target frameworks of `net5.0` or higher.
             </Callout>
 
-            Unsupported:
-
-            ```xml
-            <TargetFramework>net452</TargetFramework>
-            ```
-
             If you want to monitor an ASP.NET Core application targeting .NET Framework, ensure that you have enabled the .NET Framework support after installing the .NET agent.
         </Collapser>
 
@@ -343,7 +353,7 @@ Want to try out our .NET agent? [Create a New Relic account](https://newrelic.co
         >
             The .NET agent automatically instruments these application frameworks:
 
-            * ASP.NET Core MVC 2.0, 2.1, 2.2, 3.0, 3.1, 5.0, 6.0, 7.0, and 8.0 (includes Web API)
+            * ASP.NET Core MVC 2.0, 2.1, 2.2, 3.0, 3.1, 5.0, 6.0, 7.0, 8.0, and 9.0 (includes Web API)
             * ASP.NET Core Razor Pages 6.0, 7.0, and 8.0 (starting with .NET agent version 10.19.0)
         </Collapser>