chore: make bun optional for source builds

pnpm-lock.yaml

@@ -197,6 +197,9 @@ importers:
       signal-utils:
         specifier: ^0.21.1
         version: 0.21.1(signal-polyfill@0.2.2)
+      tsx:
+        specifier: ^4.21.0
+        version: 4.21.0
       typescript:
         specifier: ^5.9.3
         version: 5.9.3
@@ -4754,7 +4757,6 @@ snapshots:
   get-tsconfig@4.13.0:
     dependencies:
       resolve-pkg-maps: 1.0.0
-    optional: true
 
   glob-parent@5.1.2:
     dependencies:
@@ -5515,8 +5517,7 @@ snapshots:
 
   require-from-string@2.0.2: {}
 
-  resolve-pkg-maps@1.0.0:
-    optional: true
+  resolve-pkg-maps@1.0.0: {}
 
   retry@0.12.0: {}
 
@@ -5838,7 +5839,6 @@ snapshots:
       get-tsconfig: 4.13.0
     optionalDependencies:
       fsevents: 2.3.3
-    optional: true
 
   type-is@2.0.1:
     dependencies: