feat: refactor HTTP client setup for Github and Forgejo services

- Centralized HTTP client configuration for `GithubService` and `ForgejoService` using `AddHttpClient`.
- Enhanced maintainability by moving Forgejo token and base URL setup into DI-configured HTTP clients.
- Fixed `forgejoInstance` validation logic and adjusted release selection to prioritize the first non-prerelease.

Services/ForgejoService.cs

@@ -20,7 +20,6 @@ public class ForgejoService(HttpClient httpClient, AppConfig config, ILogger<For
                 HttpMethod.Post,
                 new Uri($"{config.ForgejoInstacne}/api/v1/repos/{owner}/{repo}/releases"));
             request.Content = new StringContent(json, Encoding.UTF8, "application/json");
-            request.Headers.Authorization = new AuthenticationHeaderValue("token", config.ForgejoToken);
 
             using var response = await httpClient.SendAsync(request, token);
             response.EnsureSuccessStatusCode();
@@ -79,7 +78,6 @@ public class ForgejoService(HttpClient httpClient, AppConfig config, ILogger<For
                 HttpMethod.Post,
                 new Uri($"{config.ForgejoInstacne}/api/v1/repos/{owner}/{repo}/releases/{releaseId}/assets"));
             request.Content = formData;
-            request.Headers.Authorization = new AuthenticationHeaderValue("token", config.ForgejoToken);
 
             using var response = await httpClient.SendAsync(
                 request, HttpCompletionOption.ResponseHeadersRead, token);