Publish edge rad CLI binaries to ./rad instead of `./dist/os_arch/r…

…elease/rad` (radius-project#6634)

# Description

This fixes the edge rad publishing to be just the binary instead of the
full path

## Type of change

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Fixes: radius-project#6633

## Auto-generated summary

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### <samp>🤖 Generated by Copilot at 5d814c2</samp>

### Summary
:package::whale::zap:

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1. :package: This emoji represents the packaging or bundling of the rad
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The pull request optimizes the image size and structure of the `rad` cli
binaries by copying them to the root directory before pushing them with
`oras`. The change affects the `.github/workflows/build.yaml` file.

> _`rad` binary copied_
> _to root before container push_
> _smaller image, spring cleaning_

### Walkthrough
* Copy rad binary to root directory before pushing to container registry
([link](https://github.com/radius-project/radius/pull/6634/files?diff=unified&w=0#diff-d0777657fa3fd81d23aaf7273e58aee453b04e67882517900c56daeef9b3e4c1L219-R225))

Signed-off-by: willdavsmith <willdavsmith@gmail.com>

.github/workflows/build.yaml

@@ -216,11 +216,13 @@ jobs:
       - name: Push latest rad cli binary to GHCR (unix-like)
         if: github.ref == 'refs/heads/main' && matrix.target_os != 'windows'
         run: |
-          oras push ${{ env.CONTAINER_REGISTRY }}/rad/${{ matrix.target_os }}-${{ matrix.target_arch }}:latest ./dist/${{ matrix.target_os}}_${{ matrix.target_arch}}/release/rad --annotation "org.opencontainers.image.source=${{ env.IMAGE_SRC }}"
+          cp ./dist/${{ matrix.target_os}}_${{ matrix.target_arch}}/release/rad ./rad
+          oras push ${{ env.CONTAINER_REGISTRY }}/rad/${{ matrix.target_os }}-${{ matrix.target_arch }}:latest ./rad --annotation "org.opencontainers.image.source=${{ env.IMAGE_SRC }}"
       - name: Copy cli binaries to release (windows)
         if: github.ref == 'refs/heads/main' && matrix.target_os == 'windows'
         run: |
-          oras push ${{ env.CONTAINER_REGISTRY }}/rad/${{ matrix.target_os }}-${{ matrix.target_arch }}:latest ./dist/${{ matrix.target_os}}_${{ matrix.target_arch}}/release/rad.exe --annotation "org.opencontainers.image.source=${{ env.IMAGE_SRC }}"
+          cp ./dist/${{ matrix.target_os}}_${{ matrix.target_arch}}/release/rad.exe ./rad.exe
+          oras push ${{ env.CONTAINER_REGISTRY }}/rad/${{ matrix.target_os }}-${{ matrix.target_arch }}:latest .rad.exe --annotation "org.opencontainers.image.source=${{ env.IMAGE_SRC }}"
 
   build-and-push-images:
     name: Build and publish container images