chore(testdata): updates test expectations to match new error messaging

testdata/get__missing__err.ct

@@ -1,14 +1,2 @@
 $ pda get foobar --> FAIL
-Error: Key not found
-Usage:
-  pda get KEY[@DB] [flags]
-
-Aliases:
-  get, g
-
-Flags:
-  -h, --help             help for get
-  -b, --include-binary   include binary data in text output
-      --no-template      directly output template syntax
-  -c, --run              execute the result as a shell command
-      --secret           display values marked as secret
+Error: cannot get 'foobar': Key not found