[🔥AUDIT🔥] Add missing package.json keys that are needed for OIDC (#92)

🖍 _This is an audit!_ 🖍

## Summary:

Trusted Publishing (OIDC) requires a `repository` key in the `package.json` with a `url` defined. 

This PR adds the required fields and hopefully fixes the last publish issue. 

Error:

```
🦋  info npm info @khanacademy/graphql-flow
🦋  info @khanacademy/graphql-flow is being published because our local version (3.4.2) has not been published on npm
🦋  info Publishing "@khanacademy/graphql-flow" at "3.4.2"
🦋  error an error occurred while publishing @khanacademy/graphql-flow: E422 422 Unprocessable Entity - PUT https://registry.npmjs.org/@khanacademy%2fgraphql-flow - Error verifying sigstore provenance bundle: Failed to validate repository information: package.json: "repository.url" is "", expected to match "https://github.com/Khan/graphql-flow" from provenance
🦋  error npm notice SECURITY NOTICE: Breaking changes starting October 13, 2025. New tokens will be limited to a maximum lifetime of 90 days, and TOTP setup will be disabled. Classic tokens will be revoked in November. Update your CI/CD workflows to avoid disruption. Learn more: https://gh.io/npm-token-changes
🦋  error npm notice Publishing to https://registry.npmjs.org with tag latest and public access
🦋  error npm notice publish Signed provenance statement with source and build information from GitHub Actions
🦋  error npm notice publish Provenance statement published to transparency log: https://search.sigstore.dev/?logIndex=653196413
🦋  error npm error code E422
🦋  error npm error 422 Unprocessable Entity - PUT https://registry.npmjs.org/@khanacademy%2fgraphql-flow - Error verifying sigstore provenance bundle: Failed to validate repository information: package.json: "repository.url" is "", expected to match "https://github.com/Khan/graphql-flow" from provenance
🦋  error npm error A complete log of this run can be found in: /home/runner/.npm/_logs/2025-10-29T22_19_58_512Z-debug-0.log
🦋  error
🦋  error packages failed to publish:
🦋  @khanacademy/graphql-flow@3.4.2
```


Issue: "none"

## Test plan:

Hrm

Author: jeremywiebe

Auditors: jaredly

Required Reviewers:

Approved By:

Checks: ✅ 1 check was successful

Pull Request URL: #92

Author: jeremywiebe

package.json

@@ -1,6 +1,13 @@
 {
     "name": "@khanacademy/graphql-flow",
     "version": "3.4.2",
+    "repository": {
+        "type": "git",
+        "url": "https://github.com/Khan/graphql-flow.git"
+    },
+    "bugs": {
+        "url": "https://github.com/Khan/graphql-flow/issues"
+    },
     "publishConfig": {
         "access": "public",
         "provenance": true