chore: fix alpha build of lambda-go/python packages

Now that the hard-coded refernces to @aws-cdk/aws-lambda have been removed from
these packages, we can publish them as "normal" alpha modules. This just
involves removing the special config from both package.jsons.

Note this is also forward-porting #15994 from master, which was missed in the
original change to make these packages v2-compliant. We _could_ just wait for
the next forward merge job, but wanting to close this out while I still have
context.

closes #15586
closes #15585

packages/@aws-cdk/aws-lambda-go/package.json

@@ -103,6 +103,5 @@
   "publishConfig": {
     "tag": "next"
   },
-  "separate-module": false,
   "private": true
 }

packages/@aws-cdk/aws-lambda-python/package.json

@@ -100,7 +100,6 @@
       "docker"
     ]
   },
-  "separate-module": false,
   "publishConfig": {
     "tag": "latest"
   }

packages/@aws-cdk/aws-lambda-python/test/function.test.ts

@@ -48,7 +48,7 @@ test('PythonFunction with defaults', () => {
   });
 
   expect(bundle).toHaveBeenCalledWith(expect.objectContaining({
-    entry: expect.stringMatching(/@aws-cdk\/aws-lambda-python\/test\/lambda-handler$/),
+    entry: expect.stringMatching(/aws-lambda-python\/test\/lambda-handler$/),
     outputPathSuffix: '.',
   }));
 
@@ -65,7 +65,7 @@ test('PythonFunction with index in a subdirectory', () => {
   });
 
   expect(bundle).toHaveBeenCalledWith(expect.objectContaining({
-    entry: expect.stringMatching(/@aws-cdk\/aws-lambda-python\/test\/lambda-handler-sub$/),
+    entry: expect.stringMatching(/aws-lambda-python\/test\/lambda-handler-sub$/),
     outputPathSuffix: '.',
   }));
 
@@ -142,4 +142,4 @@ test('allows specifying hash type', () => {
       S3Key: 'MY_CUSTOM_HASH',
     },
   });
-});
+});