remove word calc from warning block

src/pages/docs/projects/variables/variable-substitutions.mdx

@@ -93,7 +93,7 @@ Basic mathematical calculations are supported in Octopus using the `calc` statem
 - Division - `/`
 
 :::div{.warning}
-When using a variable on the left-hand-side of a divide (`/`) or subtraction (`-`) calc operation,
+When using a variable on the left-hand-side of a divide (`/`) or subtraction (`-`) operation,
 the variable name must be enclosed in braces (`{ ... }`) to ensure correct parsing, this ensures the operator symbol is recognised
 as an operation, rather than part of the variable name. 
 :::