[Bug][Amazon Linux 2]: zstd RPM compression conflicts with rpm 4.11.3

[n-nagornyi]

Important Note: NVIDIA AI Enterprise customers can get support from NVIDIA Enterprise support. Please open a case here.

Describe the bug
nvidia-container-toolkit and libnvidia-container RPM compression switched since 1.19.0 from gzip to zstd without a heads-up. Amazon Linux 2 provides rpm 4.11.3 which doesn't support zstd compression which makes it impossible to update nvidia-container-toolkit to >= 1.19.0. Amazon Linux 2 doesn't plan to bump rpm version.

To Reproduce

1. Run an x86_64 EC2 instance with an AMI which name starts from amzn2-ami-minimal-hvm-2.0.2026. For example, amzn2-ami-ecs-kernel-5.10-gpu-hvm-2.0.20260714-x86_64-ebs.
2. curl -s -L https://nvidia.github.io/libnvidia-container/stable/rpm/nvidia-container-toolkit.repo | sudo tee /etc/yum.repos.d/nvidia-container-toolkit.repo
3. sudo yum install nvidia-container-toolkit

ERROR You need to update rpm to handle:
rpmlib(PayloadIsZstd) <= 5.4.18-1 is needed by libnvidia-container1-1.19.1-1.x86_64
rpmlib(PayloadIsZstd) <= 5.4.18-1 is needed by nvidia-container-toolkit-1.19.1-1.x86_64
rpmlib(PayloadIsZstd) <= 5.4.18-1 is needed by libnvidia-container-tools-1.19.1-1.x86_64
rpmlib(PayloadIsZstd) <= 5.4.18-1 is needed by nvidia-container-toolkit-base-1.19.1-1.x86_64
RPM needs to be updated

Expected behavior
RPM compression reverted back to gzip to support wider range of Linux distros, including older versions.

[n-nagornyi]

Please take a look if #1950 makes sense to you.

[henry118]

PR merged