ci: Use Cirrus "greedy" flag to use idle CPU time when available

Author: real-or-random

.cirrus.yml

@@ -50,14 +50,18 @@ merge_base_script_snippet: &MERGE_BASE
     - git config --global user.name "ci"
     - git merge FETCH_HEAD  # Merge base to detect silent merge conflicts
 
-task:
-  name: "x86_64: Linux (Debian stable)"
+linux_container_snippet: &LINUX_CONTAINER
   container:
     dockerfile: ci/linux-debian.Dockerfile
     # Reduce number of CPUs to be able to do more builds in parallel.
     cpu: 1
+    greedy: true
     # More than enough for our scripts.
     memory: 1G
+
+task:
+  name: "x86_64: Linux (Debian stable)"
+  << : *LINUX_CONTAINER
   matrix: &ENV_MATRIX
     - env: { WIDEMUL:  int64, RECOVERY: yes, ECDH: yes, EXPERIMENTAL: yes, SCHNORRSIG: yes }
     - env: { WIDEMUL: int128, RECOVERY: yes, ECDH: yes, EXPERIMENTAL: yes, SCHNORRSIG: yes }
@@ -81,10 +85,7 @@ task:
 
 task:
   name: "i686: Linux (Debian stable)"
-  container:
-    dockerfile: ci/linux-debian.Dockerfile
-    cpu: 1
-    memory: 1G
+  << : *LINUX_CONTAINER
   env:
     HOST: i686-linux-gnu
     ECDH: yes
@@ -167,10 +168,7 @@ task:
 
 task:
   name: "s390x (big-endian): Linux (Debian stable, QEMU)"
-  container:
-    dockerfile: ci/linux-debian.Dockerfile
-    cpu: 1
-    memory: 1G
+  << : *LINUX_CONTAINER
   env:
     WRAPPER_CMD: qemu-s390x
     SECP256K1_TEST_ITERS: 16
@@ -190,10 +188,7 @@ task:
 
 task:
   name: "ARM32: Linux (Debian stable, QEMU)"
-  container:
-    dockerfile: ci/linux-debian.Dockerfile
-    cpu: 1
-    memory: 1G
+  << : *LINUX_CONTAINER
   env:
     WRAPPER_CMD: qemu-arm
     SECP256K1_TEST_ITERS: 16
@@ -214,10 +209,7 @@ task:
 
 task:
   name: "ARM64: Linux (Debian stable, QEMU)"
-  container:
-    dockerfile: ci/linux-debian.Dockerfile
-    cpu: 1
-    memory: 1G
+  << : *LINUX_CONTAINER
   env:
     WRAPPER_CMD: qemu-aarch64
     SECP256K1_TEST_ITERS: 16
@@ -235,10 +227,7 @@ task:
 
 task:
   name: "ppc64le: Linux (Debian stable, QEMU)"
-  container:
-    dockerfile: ci/linux-debian.Dockerfile
-    cpu: 1
-    memory: 1G
+  << : *LINUX_CONTAINER
   env:
     WRAPPER_CMD: qemu-ppc64le
     SECP256K1_TEST_ITERS: 16
@@ -256,10 +245,7 @@ task:
 
 task:
   name: "x86_64 (mingw32-w64): Windows (Debian stable, Wine)"
-  container:
-    dockerfile: ci/linux-debian.Dockerfile
-    cpu: 1
-    memory: 1G
+  << : *LINUX_CONTAINER
   env:
     WRAPPER_CMD: wine64-stable
     SECP256K1_TEST_ITERS: 16
@@ -277,9 +263,8 @@ task:
 
 # Sanitizers
 task:
+  << : *LINUX_CONTAINER
   container:
-    dockerfile: ci/linux-debian.Dockerfile
-    cpu: 1
     memory: 2G
   env:
     ECDH: yes
@@ -322,10 +307,7 @@ task:
 
 task:
   name: "C++ -fpermissive"
-  container:
-    dockerfile: ci/linux-debian.Dockerfile
-    cpu: 1
-    memory: 1G
+  << : *LINUX_CONTAINER
   env:
     # ./configure correctly errors out when given CC=g++.
     # We hack around this by passing CC=g++ only to make.