Release ink! 3.0.0-rc4 (#864)

* Add `Fixed` entry for #842

* Replace `3.0.0-rc3` with `3.0.0-rc4`

* Add bump allocator to release notes
19 jobs for v3.0.0-rc4 in 15 minutes and 12 seconds (queued for 3 seconds)
latest
Status Job ID Name Coverage
  Check
passed #1028245
linux-docker
check-std

00:02:17

passed #1028246
linux-docker
check-wasm

00:01:49

 
  Workspace
passed #1028247
linux-docker
build-std

00:02:25

passed #1028248
linux-docker
build-wasm

00:02:03

passed #1028252
linux-docker
clippy-std

00:02:29

passed #1028253
linux-docker
clippy-wasm

00:01:32

passed #1028250
linux-docker
docs

00:01:15

passed #1028254
linux-docker
fmt

00:01:04

passed #1028251
linux-docker
spellcheck

00:00:34

passed #1028249
linux-docker
test

00:04:25

 
  Examples
passed #1028258
linux-docker
examples-clippy-std

00:01:42

passed #1028259
linux-docker
examples-clippy-wasm

00:01:11

passed #1028260
linux-docker
examples-contract-build

00:06:38

passed #1028261
linux-docker
examples-contract-build-delegator

00:04:11

passed #1028262
linux-docker
examples-docs

00:01:43

passed #1028257
linux-docker
examples-fmt

00:00:17

passed #1028255
linux-docker
examples-test

00:01:51

passed #1028256
linux-docker
examples-test-experimental-engine

00:01:25

 
  Ink Waterfall
failed #1028263
kubernetes-parity-build allowed to fail
ink-waterfall

00:01:48

 
Name Stage Failure
failed
ink-waterfall Ink Waterfall

Triggered pipeline status is running

Triggered pipeline status is running

Triggered pipeline status is failed
Something's broken in: "https://gitlab.parity.io/parity/ink-waterfall/-/pipelines/148747"
Cleaning up file based variables
ERROR: Job failed: command terminated with exit code 1