[@azure/eventgrid-system-events] Fix typo in package.json (#30094)

### Packages impacted by this PR

@azure/eventgrid-system-events

### Issues associated with this PR


### Describe the problem that is addressed by this PR

Fix typo in package.json

### What are the possible designs available to address the problem? If
there are more than one possible design, why was the one in this PR
chosen?


### Are there test cases added in this PR? _(If not, why?)_


### Provide a list of related PRs _(if any)_


### Command used to generate this PR:**_(Applicable only to SDK release
request PRs)_

### Checklists
- [X] Added impacted package name to the issue description
- [ ] Does this PR needs any fixes in the SDK Generator?** _(If so,
create an Issue in the
[Autorest/typescript](https://github.com/Azure/autorest.typescript)
repository and link it here)_
- [ ] Added a changelog (if necessary)

sdk/eventgrid/eventgrid-system-events/package.json

@@ -27,7 +27,7 @@
   "files": [
     "dist/",
     "dist-esm/src/",
-    "types/eventgrid-sysem-events.d.ts",
+    "types/eventgrid-system-events.d.ts",
     "README.md",
     "LICENSE"
   ],