Remove Pygmalion instruct template (duplicate of Metharme)

ST already applies user sequence as stop string, so Pygmalion's <|user|> stop_sequence is meaningless.

default/content/presets/context/Metharme.json

@@ -6,5 +6,5 @@
     "always_force_name2": true,
     "trim_sentences": false,
     "single_line": false,
-    "name": "Pygmalion"
+    "name": "Metharme"
 }