Merge #19746: ci: Move valgrind fuzzer to cirrus

fa0538e94d ci: Set cirrus RAM to 8GB (MarcoFalke)
fa41810d0e ci: Run valgrind fuzzer on cirrus (MarcoFalke)

Pull request description:

  The first commit should fix the 50min timeout in forked repos. Similar to #19424. E.g. https://travis-ci.org/github/bitcoin-core/gui/builds/718322267

  The second commit should fix #19744

Top commit has no ACKs.

Tree-SHA512: c765098dfa913ca49b1d1eee99aaa83e4b9eb191b7ad5e652e3f04744fe8670dd3ef4215832b8e2b5bac0273d24f607fc275e72f566326108ba42ab57228ffd4

.cirrus.yml

@@ -5,7 +5,7 @@ container:
   # https://cirrus-ci.org/faq/#are-there-any-limits
   # Each project has 16 CPU in total, assign 2 to each container, so that 8 tasks run in parallel
   cpu: 2
-  memory: 6G  # https://cirrus-ci.org/guide/linux/#linux-containers
+  memory: 8G  # Set to 8GB to avoid OOM. https://cirrus-ci.org/guide/linux/#linux-containers
 env:
   PACKAGE_MANAGER_INSTALL : "apt-get update && apt-get install -y"
   MAKEJOBS: "-j4"
@@ -66,3 +66,11 @@ task:
     image: ubuntu:focal
   env:
     FILE_ENV: "./ci/test/00_setup_env_native_asan.sh"
+
+task:
+  name: 'x86_64 Linux  [GOAL: install]  [focal]  [no depends, only system libs, fuzzers under valgrind]'
+  << : *GLOBAL_TASK_TEMPLATE
+  container:
+    image: ubuntu:focal
+  env:
+    FILE_ENV: "./ci/test/00_setup_env_native_fuzz_with_valgrind.sh"

.travis.yml

@@ -109,11 +109,6 @@ jobs:
       env: >-
         FILE_ENV="./ci/test/00_setup_env_native_multiprocess.sh"
 
-    - stage: test
-      name: 'x86_64 Linux  [GOAL: install]  [focal]  [no depends, only system libs, fuzzers under valgrind]'
-      env: >-
-        FILE_ENV="./ci/test/00_setup_env_native_fuzz_with_valgrind.sh"
-
     - stage: test
       name: 'x86_64 Linux  [GOAL: install]  [xenial]  [no wallet]'
       env: >-