🔧 Update OpenApiPlugin paths (microsoft#127)

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Updated OpenApiPlugin paths from `CopilotChat/Skills` to `Skills` in
ChatController.cs.
Also added autogenerated sln file to .gitignore

### Contribution Checklist

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- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [Contribution
Guidelines](https://github.com/microsoft/copilot-chat/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/copilot-chat/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
~~- [ ] All unit tests pass, and I have added new tests where possible~~
- [x] I didn't break anyone 😄

.gitignore

@@ -480,4 +480,7 @@ webapp/build/
 webapp/node_modules/
 
 # Custom plugin files used in webapp for testing
-webapp/public/.well-known*
+webapp/public/.well-known*
+
+# Auto-generated solution file from Visual Studio
+webapi/CopilotChatWebApi.sln

webapi/Controllers/ChatController.cs

@@ -184,7 +184,7 @@ private async Task RegisterPlannerSkillsAsync(CopilotChatPlanner planner, Dictio
             BearerAuthenticationProvider authenticationProvider = new(() => Task.FromResult(GithubAuthHeader));
             await planner.Kernel.ImportAIPluginAsync(
                 skillName: "GitHubPlugin",
-                filePath: Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!, "CopilotChat", "Skills", "OpenApiPlugins/GitHubPlugin/openapi.json"),
+                filePath: Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!, "Skills", "OpenApiPlugins/GitHubPlugin/openapi.json"),
                 new OpenApiSkillExecutionParameters
                 {
                     AuthCallback = authenticationProvider.AuthenticateRequestAsync,
@@ -200,7 +200,7 @@ await planner.Kernel.ImportAIPluginAsync(
 
             await planner.Kernel.ImportAIPluginAsync(
                 skillName: "JiraPlugin",
-                filePath: Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!, "CopilotChat", "Skills", "OpenApiPlugins/JiraPlugin/openapi.json"),
+                filePath: Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!, "Skills", "OpenApiPlugins/JiraPlugin/openapi.json"),
                 new OpenApiSkillExecutionParameters
                 {
                     AuthCallback = authenticationProvider.AuthenticateRequestAsync,