Fix - not recognized in $(…) syntax.

Author: sharpjs

CHANGES.md

@@ -7,6 +7,7 @@ Most lines should begin with one of these words:
 ## [Unreleased](https://github.com/sharpjs/Prequel/compare/release/1.0.3..HEAD)
 - Change license from ISC to MIT.
 - Add .NET 8.0 target framework.
+- Fix `-` not recognized in `$(…)` syntax.
 
 <!--
 ## [1.1.0](https://github.com/sharpjs/Prequel/compare/release/1.0.3..release/1.1.0)

Prequel/SqlCmdPreprocessor.cs

@@ -444,7 +444,7 @@ public void AppendRangeTo(StringBuilder builder, int start, int end)
 
     private static readonly Regex VariableRegex = new(
         """
-        \$\( (?<name>\w+) \)
+        \$\( (?<name> [\w-[\d]] [-\w]* ) \)
         """,
         Options
     );
@@ -466,7 +466,7 @@ public void AppendRangeTo(StringBuilder builder, int start, int end)
         """
         \A [ \t]+
 
-        (?<name> [\w-[0-9]] [\w-]* )
+        (?<name> [\w-[\d]] [-\w]* )
 
         (?> [ \t]+
             (?<value> [^" \t\r\n]+                  # unquoted