chore: docker compose v2

The `docker-compose` command has been replaced by `docker compose`.
The "version" tag has also been deprecated in docker-compose.yml.

.github/workflows/check.yml

@@ -32,11 +32,11 @@ jobs:
         else
           echo "OK $nb CVEs reported"
         fi
-    - name: check docker-compose run execution
+    - name: check docker compose run execution
       run: |
         expected=19
-        docker-compose build
-        nb=$(docker-compose run --rm spectre-meltdown-checker --batch json | jq '.[]|.CVE' | wc -l)
+        docker compose build
+        nb=$(docker compose run --rm spectre-meltdown-checker --batch json | jq '.[]|.CVE' | wc -l)
         if [ "$nb" -ne "$expected" ]; then
           echo "Invalid number of CVEs reported: $nb instead of $expected"
           exit 1

README.md

@@ -76,10 +76,13 @@ sudo ./spectre-meltdown-checker.sh
 #### With docker-compose
 
 ```shell
-docker-compose build
-docker-compose run --rm spectre-meltdown-checker
+docker compose build
+docker compose run --rm spectre-meltdown-checker
 ```
 
+Note that on older versions of docker, `docker-compose` is a separate command, so you might
+need to replace the two `docker compose` occurences above by `docker-compose`.
+
 #### Without docker-compose
 
 ```shell

docker-compose.yml

@@ -1,5 +1,3 @@
-version: '2'
-
 services:
   spectre-meltdown-checker:
     build: