chore: remove tg channel

Author: RuslanGlaznyov

user-and-dev-tools/mainnet/explorers.json

@@ -61,14 +61,5 @@
     "Short Description": "",
     "Team or Contributor Name": "Coverlet",
     "GitHub Account": "https://github.com/coverlet"
-  }, 
-  {
-    "Explorer Name": "Namada announcement telegram mirror",
-    "URL": "https://t.me/namadaupdates",
-    "Image URL": "",
-    "Available": "yes",
-    "Short Description": "A mirror of the Namada announcement telegram channel",
-    "Team or Contributor Name": "MELLIFERA",
-    "GitHub Account": "mellifera-labs"
-  }
+  } 
 ]