Remove unused Rococo parachains runtimes

[acatangiu]

Rococo has been decomissioned some while ago. We still kept the runtimes for Rococo<>Westend bridge zombienet and integration tests. This commit removes the unused runtimes and obsolete integration tests.

Removed:

• coretime-rococo
• people-rococo

Kept:

• asset-hub-rococo
• bridge-hub-rococo
• rococo relay chain

Which are still being used/useful for R<>W bridge testing.

Also remove RAH integration tests which are obsolete. WAH integration tests cover all AH usecases.

This cleanup decreases maintenance burden (all FRAME changes had to be integrated to these defunct runtimes) and CI overhead: fewer tests to run.

[github-actions]

The PR removes unused Rococo runtimes and integration tests, which is good cleanup. However, there are several lingering references to the removed runtimes in cumulus/polkadot-parachain (the node binary) and polkadot/zombienet-sdk-tests. These references will cause compilation errors because the runtime crates have been removed from the workspace and dependencies. You need to remove the code that depends on these runtimes.

---

Review Suggestions

cumulus/polkadot-parachain/src/chain_spec/mod.rs:33, 59, 205-206, 335-336

This file still references rococo_parachain module and rococo_parachain_runtime (indirectly or in tests), which has been removed. The rococo_parachain module declaration and usage should be removed. The fallback to rococo_parachain_local_config also needs to be removed or updated.

---

cumulus/polkadot-parachain/src/chain_spec/people.rs:67-79, 118-149

The PeopleRuntimeType::Rococo* variants and the rococo module reference people_rococo_runtime, which has been removed. These should be removed.

---

cumulus/polkadot-parachain/src/chain_spec/coretime.rs:110-116, 144-184

The CoretimeRuntimeType::Rococo* variants and the rococo module reference coretime_rococo_runtime, which has been removed. These should be removed.

---

cumulus/polkadot-parachain/src/chain_spec/rococo_parachain.rs:1-78

This file uses rococo_parachain_runtime, which has been removed. This file should likely be deleted.

---

polkadot/zombienet-sdk-tests/build.rs:135

coretime-rococo is still in the CHAINS list. This will cause the build script to try and build coretime-rococo-runtime, which will fail.

---

polkadot/zombienet-sdk-tests/tests/smoke/coretime_revenue.rs:14-15, 245

This test relies on coretime-rococo metadata and chain spec. Since coretime-rococo is being removed, this test should probably be removed or adapted.

---

polkadot/zombienet-sdk-tests/tests/elastic_scaling/doesnt_break_parachains.rs:50

The comment references rococo-parachain. Verify if the test logic relies on rococo-parachain behavior or if it needs adjustment.