build(devcontainer): upgrade docker engine to v26.x.y in the image

1. This will help us with newer features and also potential CVEs in the
(now) quite outdated version we were using before.

Signed-off-by: Peter Somogyvari <peter.somogyvari@accenture.com>

.devcontainer/devcontainer.json

@@ -9,7 +9,7 @@
 		"ghcr.io/devcontainers/features/docker-outside-of-docker:1": {
 			"moby": true,
 			"installDockerBuildx": true,
-			"version": "20.10.24",
+			"version": "26.1.4",
 			"dockerDashComposeVersion": "v2"
 		},
 		"ghcr.io/devcontainers/features/git:1": {