chore(nextnet): version bump nextnet to 0.50.0-rc.0 (#5452)

Description
---
Version bump nextnet to 0.50.0-rc.0

Motivation and Context
---
Moving forward!

Breaking Changes
---

- [ ] None
- [ ] Requires data directory on base node to be deleted
- [x] Requires hard fork
- [ ] Other - Please specify

<!-- Does this include a breaking change? If so, include this line as a
footer -->
<!-- BREAKING CHANGE: Description what the user should do, e.g. delete a
database, resync the chain -->

.config/nextest.toml

@@ -0,0 +1,2 @@
+[profile.ci.junit]  # this can be some other profile, too
+path = "junit.xml"

.gitignore

@@ -64,3 +64,4 @@ clients/wallet_grpc_client/package-lock.json
 pie/
 /integration_tests/.husky/_/husky.sh
 /integration_tests/tests/temp
+integration_tests/cucumber-output-junit.xml