feature: tag from ci fetches commits from remote api

src/git_flow/remote/gitlab.py

@@ -2,6 +2,7 @@ from urllib.parse import quote
 
 import requests
 from git_flow import GitFlowError
+from git_flow.git import Commit
 from git_flow.remote.base import RemoteAPI
 
 
@@ -47,6 +48,28 @@ class GitlabRemoteAPI(RemoteAPI):
         else:
             raise GitFlowError("Ocurrió un error al crear el tag para repositorio " + quote(self.repository, safe="") + ": " + response.text)
 
+    def get_merge_commits(self, merge_commit: str) -> list[Commit]:
+        mrs = self.get_json(
+            self.get_endpoint(f"/repository/commits/{merge_commit}/merge_requests")
+        ).json()
+        mr = next((m for m in mrs if m.get("merge_commit_sha") == merge_commit), None)
+
+        if not mr:
+            raise GitFlowError(f"No se encontró un MR para el commit {merge_commit}")
+
+        items = self.get_all_pages(self.get_endpoint(f"/merge_requests/{mr['iid']}/commits"), 100)
+
+        # GitLab ya los devuelve del más nuevo al más viejo
+        return [
+            Commit(
+                c["short_id"][:7],
+                c["title"],
+                c["author_email"],
+                len(c["parent_ids"]) > 1,
+            )
+            for c in items
+        ]
+
     def get_endpoint(self, resource: str) -> str:
         project_id = quote(self.repository, safe="")
         return f"{self.base_url}/api/v4/projects/{project_id}{resource}"