Customize schedule with runtime memory limit suitable for development node (#187)

In recent PR
https://github.com/paritytech/substrate-contracts-node/pull/182#issuecomment-1536514910,
the CI step of running `cargo test` was commented out as a dirty
workaround for the pallet contracts integrity test failure. The test
checks that the pallet configuration is memory safe.

So to make the test pass, we enlarge the runtime memory limit in the
Schedule. We do this because this development node
[allows](https://github.com/paritytech/substrate-contracts-node/blob/8d13ddef3f5c728d1661e79c511a28cef206b298/runtime/src/lib.rs#L367)
larger contract size than it is normally allowed in a production running
node. This should be fine for the development node where possible
security implications could be neglected for the sake of development
convenience. **However, please DO NOT do this to your production node
config, unless you are sure that the limit you're setting is the real
memory limit of your runtime**.