Use suitable base images in tests

Author: jgarber623-cargosense

test/shellcheck/scenarios.json

@@ -1,15 +1,15 @@
 {
   "shellcheck-version": {
-    "image": "debian:latest",
+    "image": "mcr.microsoft.com/devcontainers/base:debian",
     "features": {
       "shellcheck": {
-        "version": "0.5.0"
+        "version": "0.7.0"
       }
     }
   },
 
   "shellcheck-install-path": {
-    "image": "debian:latest",
+    "image": "mcr.microsoft.com/devcontainers/base:debian",
     "features": {
       "shellcheck": {
         "installPath": "/usr/bin"

test/shellcheck/shellcheck-version.sh

@@ -11,7 +11,7 @@ source dev-container-features-test-lib
 # Feature-specific tests
 # The 'check' command comes from the dev-container-features-test-lib. Syntax is...
 # check <LABEL> <cmd> [args...]
-check "version" bash -c "shellcheck --version | grep 0.5.0"
+check "version" bash -c "shellcheck --version | grep 0.7.0"
 
 # Report result
 # If any of the checks above exited with a non-zero exit code, the test will fail.