fix(py): Clean up webhook snippets (#4864)

Author: mgaeta

src/docs/product/integrations/integration-platform/webhooks.mdx

@@ -51,15 +51,22 @@ function verifySignature(request, secret = "") {
 ```
 
 ```python
-    body = json.dumps(request.body)
-    expected = hmac.new(
-        key=client_secret.encode('utf-8'),
-        msg=body,
-        digestmod=sha256,
-    ).hexdigest()
-
-    if expected != request.headers['Sentry-Hook-Signature']:
-            raise UnauthorizedError
+import hashlib
+import hmac
+import json
+
+expected_digest = request.headers['sentry-hook-signature']
+body = json.dumps(request.body)
+
+digest = hmac.new(
+    key=client_secret.encode('utf-8'),
+    msg=body,
+    digestmod=hashlib.sha256,
+).hexdigest()
+
+
+if digest != expected_digest:
+    raise UnauthorizedError
 ```
 
 ## Request Structure
@@ -83,31 +90,28 @@ actor
 : The actor is who, if anyone, triggered the webhook. If a user in Sentry triggered the action, then the actor is the user. If the Sentry App itself triggers the action, then the actor is the Application. And if the action is triggered automatically somehow within Sentry, then the actor is ‘Sentry.’
 
 ```python
-    # Samples cases:
-
-    # user installs sentry app
-
-    "actor": {
-      'type': 'user',
-      'id': <user-id>,
-      'name': <user-name>,
-    }
-
-    # sentry app makes request assign an issue
+# Samples cases:
 
-    "actor": {
-      'type': 'application',
-      'id': <sentry-app-uuid>,
-      'name': <sentry-app-name>,
-    },
+# User installs sentry app
+"actor": {
+    "type": "user",
+    "id": <user-id>,
+    "name": <user-name>,
+}
 
-    # sentry (sentry.io) auto resolves an issue
+# Sentry app makes request assign an issue
+"actor": {
+    "type": "application",
+    "id": <sentry-app-uuid>,
+    "name": <sentry-app-name>,
+}
 
-    "actor": {
-      'type': 'application',
-      'id': 'sentry',
-      'name': 'Sentry',
-    },
+# Sentry (sentry.io) auto resolves an issue
+"actor": {
+    "type": "application",
+    "id": "sentry",
+    "name": "Sentry",
+}
 ```
 
 <Note>