Update devcontainer publishing path (#6967)

# Description

This updates the devcontainer publishing path to (hopefully):

```
ghcr.io/radius-project/devcontainer-features/radcli:latest
```

This matches the container that everyone seems to be following at:
https://containers.dev/collections

In particular I don't want the repo name to be part of the path, because
we will probably change repos in the future.

## Type of change

- This pull request is a minor refactor, code cleanup, test improvement,
or other maintenance task and doesn't change the functionality of Radius
(issue link optional).


Part of: #6923

## Auto-generated summary

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copilot:all

Signed-off-by: Ryan Nowak <[email protected]>

.github/workflows/devcontainer-feature-release.yaml

@@ -28,6 +28,11 @@ jobs:
           generate-docs: "false"
           # disable validation due to used preview feature
           disable-schema-validation: "true"
+          # We handle tagging ourselves
+          disable-repo-tagging: "true"
+          # We don't want to include the repo name, being consistent without
+          # examples at https://containers.dev/collections
+          features-namespace: "devcontainer-features"
 
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

deploy/devcontainer-feature/src/radcli/README.md

@@ -8,7 +8,7 @@ This will install the latest stable release of the `rad` CLI.
 
 ```json
 "features": {
-    "ghcr.io/devcontainers/radius/radiuscli:latest": {
+    "ghcr.io/radius-project/devcontainer-features/radcli:latest": {
         "version": "latest"
     }
 }
@@ -20,7 +20,7 @@ This will install the edge (unstable) release of the `rad` CLI.
 
 ```json
 "features": {
-    "ghcr.io/devcontainers/radius/radiuscli:latest": {
+    "ghcr.io/radius-project/devcontainer-features/radcli:latest": {
         "version": "edge"
     }
 }
@@ -32,7 +32,7 @@ This will install version 0.28.0 of the `rad` CLI.
 
 ```json
 "features": {
-    "ghcr.io/devcontainers/radius/radiuscli:latest": {
+    "ghcr.io/radius-project/devcontainer-features/radcli:latest": {
         "version": "0.28.0"
     }
 }