chore: remove privatenetworks service (#3121)

Co-authored-by: Sean O'Brien <obrien.sean.dev@gmail.com>

Author: stobrien89

.changes/nextrelease/remove-privatenetworks.json

@@ -0,0 +1,7 @@
+[
+  {
+    "type": "enhancement",
+    "category": "",
+    "description": "Removes PrivateNetworks service client and models."
+  }
+]

src/PrivateNetworks/Exception/PrivateNetworksException.php

@@ -592,8 +592,6 @@
  * @method \Aws\MultiRegionClient createMultiRegionPolly(array $args = [])
  * @method \Aws\Pricing\PricingClient createPricing(array $args = [])
  * @method \Aws\MultiRegionClient createMultiRegionPricing(array $args = [])
- * @method \Aws\PrivateNetworks\PrivateNetworksClient createPrivateNetworks(array $args = [])
- * @method \Aws\MultiRegionClient createMultiRegionPrivateNetworks(array $args = [])
  * @method \Aws\PrometheusService\PrometheusServiceClient createPrometheusService(array $args = [])
  * @method \Aws\MultiRegionClient createMultiRegionPrometheusService(array $args = [])
  * @method \Aws\Proton\ProtonClient createProton(array $args = [])

src/PrivateNetworks/PrivateNetworksClient.php

@@ -2377,14 +2377,6 @@
         },
         "serviceIdentifier": "pricing"
     },
-    "privatenetworks": {
-        "namespace": "PrivateNetworks",
-        "versions": {
-            "latest": "2021-12-03",
-            "2021-12-03": "2021-12-03"
-        },
-        "serviceIdentifier": "privatenetworks"
-    },
     "proton": {
         "namespace": "Proton",
         "versions": {