fix: use console logger for health check to surface HealthCheckFailed errors

NullLogger.Instance was silently discarding the HealthCheckFailed(uri, exception)
Error-level log that ExecuteAsync emits on connection failures, TLS errors, and
DNS failures. The ILogger parameter was added to 0.0.72.928 specifically to
expose this diagnostic; use a minimal console LoggerFactory so operators can
see why a health check failed.

Prompt: Work on pull request #383 in funfair-tech/BuildBot.

Author: dnyw4l3n13

src/BuildBot/Program.cs

@@ -5,7 +5,7 @@
 using BuildBot.Helpers;
 using Credfeto.Docker.HealthCheck.Http.Client;
 using Microsoft.AspNetCore.Builder;
-using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Logging;
 
 namespace BuildBot;
 
@@ -20,13 +20,18 @@ public static class Program
     )]
     public static async Task<int> Main(string[] args)
     {
-        return HealthCheckClient.IsHealthCheck(args: args, out string? checkUrl)
-            ? await HealthCheckClient.ExecuteAsync(
+        if (HealthCheckClient.IsHealthCheck(args: args, out string? checkUrl))
+        {
+            using ILoggerFactory loggerFactory = LoggerFactory.Create(static builder => builder.AddConsole());
+
+            return await HealthCheckClient.ExecuteAsync(
                 targetUrl: checkUrl,
-                logger: NullLogger.Instance,
+                logger: loggerFactory.CreateLogger(nameof(Program)),
                 cancellationToken: CancellationToken.None
-            )
-            : await RunServerAsync(args);
+            );
+        }
+
+        return await RunServerAsync(args);
     }
 
     private static async ValueTask<int> RunServerAsync(string[] args)