cli: add experimental lazy compilation flag

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/curvy-flies-own.md

@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+Added a `EXPERIMENTAL_LAZY_COMPILATION` flag, which enables the experimental Webpack lazy compilation option in frontend builds.

packages/cli/src/lib/bundler/config.ts

@@ -224,6 +224,9 @@ export async function createConfig(
           }
         : {}),
     },
+    experiments: {
+      lazyCompilation: yn(process.env.EXPERIMENTAL_LAZY_COMPILATION),
+    },
     plugins,
     ...(withCache
       ? {