Update comment for regex 's' flag usage

Co-authored-by: rchiodo <19672699+rchiodo@users.noreply.github.com>

Author: Copilot

src/extension/common/variables/environment.ts

@@ -176,7 +176,7 @@ function parseEnvLine(line: string): [string, string] {
     //   https://github.com/motdotla/dotenv/blob/master/lib/main.js#L32
     // We don't use dotenv here because it loses ordering, which is
     // significant for substitution.
-    // Modified to handle multiline values by using 's' flag to make . match newlines
+    // Modified to handle multiline values by using 's' flag so $ matches before newlines in multiline strings
     const match = line.match(/^\s*(_*[a-zA-Z]\w*)\s*=\s*(.*?)?\s*$/s);
     if (!match) {
         return ['', ''];