[AGENT-11701] Fix TeamCity Integration (#18041)

* Handle project without builds

* Add changelog

* Refactor code

* Add comment

* Fix

* Update teamcity/changelog.d/18041.fixed

Co-authored-by: Ilia Kurenkov <ilia.kurenkov@datadoghq.com>

---------

Co-authored-by: Ilia Kurenkov <ilia.kurenkov@datadoghq.com>

teamcity/changelog.d/18041.fixed

@@ -0,0 +1 @@
+Fix handling of projects with no builds. We used to refresh all the projects whenever we encountered a build config that didn't have any builds associated with it. Now we refresh only the specific build config that's lacking builds.

teamcity/datadog_checks/teamcity/teamcity_rest.py

@@ -240,13 +240,17 @@ def _collect_build_problems(self, new_build):
     def _collect_new_builds(self, project_id):
         last_build_id = self.bc_store.get_last_build_id(project_id, self.current_build_config)
         if not last_build_id:
-            self._initialize()
+            # We want to handle the case of an unbuilt build config by checking for any last builds
+            self.log.debug(
+                'No builds for project %d and build config %d, checking again', project_id, self.current_build_config
+            )
+            ressource = "last_build"
+            options = {"project_id": project_id}
         else:
             self.log.debug('Checking for new builds...')
-            new_builds = get_response(
-                self, 'new_builds', build_conf=self.current_build_config, since_build=last_build_id
-            )
-            return new_builds
+            ressource = "new_builds"
+            options = {"since_build": last_build_id}
+        return get_response(self, ressource, build_conf=self.current_build_config, **options)
 
     def _get_build_config_type(self, build_config):
         if self.is_deployment: