Install ORAS directly from Azure Linux package feed (#1967)

The version is still 1.3.0.

@mthalman do we need to adjust anything about the renovate config since
we removed the env var and renovate comment?

Author: lbussell

src/Dockerfile.linux

@@ -2,20 +2,9 @@
 #     docker build -t image-builder .
 #     docker run --rm -v /var/run/docker.sock:/var/run/docker.sock -v <local path to build>:/repo -w /repo image-builder <image-build args>
 
-# renovate: datasource=github-releases depName=oras-project/oras
-ARG ORAS_VERSION=1.3.0
-
 # build Microsoft.DotNet.ImageBuilder
 FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:9.0-azurelinux3.0 AS build-env
 ARG TARGETARCH
-ARG ORAS_VERSION
-
-# download oras package tarball
-WORKDIR /
-RUN curl -fSL --output oras_linux.tar.gz https://github.com/oras-project/oras/releases/download/v${ORAS_VERSION}/oras_${ORAS_VERSION}_linux_${TARGETARCH}.tar.gz \
-    && mkdir -p oras-install/ \
-    && tar -zxf oras_linux.tar.gz -C oras-install/ \
-    && rm -rf oras_linux.tar.gz
 
 WORKDIR /image-builder
 
@@ -35,15 +24,13 @@ FROM mcr.microsoft.com/dotnet/runtime-deps:9.0-azurelinux3.0
 
 # install tooling
 RUN tdnf install -y \
-      moby-engine \
-      docker-cli \
       docker-buildx \
+      docker-cli \
       git \
+      moby-engine \
+      oras \
     && tdnf clean all
 
-# install oras tool
-COPY --from=build-env ["/oras-install/oras", "/usr/local/bin"]
-
 # install image-builder
 WORKDIR /image-builder
 COPY --from=build-env /image-builder/out ./