Fix: add retry logic to Esplora requests to handle connection issues

- Add timeout, max retries, and error handling to wait_for_block and wait_for_tx functions
- Catch and log connection errors instead of failing immediately
- Use shorter sleep interval (0.5s) to match Kotlin implementation
- Add helpful error messages during retries

This addresses the "Connection reset by peer" errors in CI by making the
Python tests more resilient to temporary network issues when connecting
to the Esplora API.

Author: alexanderwiederin

bindings/python/src/ldk_node/test_ldk_node.py

@@ -51,26 +51,48 @@ def mine_and_wait(esplora_endpoint, blocks):
 def wait_for_block(esplora_endpoint, block_hash):
     url = esplora_endpoint + "/block/" + block_hash + "/status"
     esplora_picked_up_block = False
-    while not esplora_picked_up_block:
-        res = requests.get(url)
+    max_retries = 30
+    retry_count = 0
+
+    while not esplora_picked_up_block and retry_count < max_retries:
         try:
-            json = res.json()
-            esplora_picked_up_block = json['in_best_chain']
-        except:
-            pass
-        time.sleep(1)
+            res = requests.get(url, timeout=10)
+            try:
+                json = res.json()
+                esplora_picked_up_block = json['in_best_chain']
+            except:
+                pass
+        except Exception as e:
+            print(f"Request error: {e}, retrying ({retry_count+1}/{max_retries})...")
+
+        retry_count += 1
+        time.sleep(0.5)
+
+    if not esplora_picked_up_block:
+        raise TimeoutError(f"Block {block_hash} not found after {max_retries} attempts")
 
 def wait_for_tx(esplora_endpoint, txid):
     url = esplora_endpoint + "/tx/" + txid
     esplora_picked_up_tx = False
-    while not esplora_picked_up_tx:
-        res = requests.get(url)
+    max_retries = 30
+    retry_count = 0
+
+    while not esplora_picked_up_tx and retry_count < max_retries:
         try:
-            json = res.json()
-            esplora_picked_up_tx = json['txid'] == txid
-        except:
-            pass
-        time.sleep(1)
+            res = requests.get(url, timeout=10)
+            try:
+                json = res.json()
+                esplora_picked_up_tx = json['txid'] == txid
+            except:
+                pass
+        except Exception as e:
+            print(f"Request error: {e}, retrying ({retry_count+1}/{max_retries})...")
+
+        retry_count += 1
+        time.sleep(0.5)
+
+    if not esplora_picked_up_tx:
+        raise TimeoutError(f"Transaction {txid} not found after {max_retries} attempts")
 
 def send_to_address(address, amount_sats):
     amount_btc = amount_sats/100000000.0