Undo change to git push origin robertbrignull/eslint-9 boolean

Author: robertbrignull

build.mjs

@@ -32,7 +32,7 @@ const context = await esbuild.context({
   outdir: "dist",
   platform: "node",
   format: "cjs",
-  sourcemap: process.env.CODEQL_VARIANT_ANALYSIS_ACTION_GENERATE_SOURCEMAPS
+  sourcemap: !!process.env.CODEQL_VARIANT_ANALYSIS_ACTION_GENERATE_SOURCEMAPS
     ? "external"
     : false,
   chunkNames: "chunks/[name]-[hash]",