[llvm] Have merge script detect whether to use https or ssh to connect to github. (PR #218380)

[Cullen Rhodes via llvm-commits]

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@@ -141,11 +141,21 @@ def load_pr_data(self):
         )
         self.prdata = json.loads(o)
 
+        # Determine if we use https or ssh to connect to github
+        remote = subprocess.run(
+            ["git", "remote", "get-url", self.args.upstream],
+            capture_output=True,
+            text=True,
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c-rhodes wrote:

add check=True?

https://github.com/llvm/llvm-project/pull/218380