Packages carry their ONNX Runtime; a DEB per Ubuntu LTS

ONNX Runtime stamps its symbols with each release's version, so the
1.0.0 RPM demanded Fedora 42's exact runtime (issue #5) and the Arch
package would break on the next update. The RPM and the Arch package
now bundle Microsoft's 1.21.0 build, as the DEB does, and the images
test against it. The RPM builds on Fedora 43. A DEB built on Ubuntu
26.04 joins 24.04's, and ubuntu.sh picks by codename.

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/install/arch.sh

@@ -21,5 +21,4 @@ curl -fL --proto '=https' -o "$work/$package" "$base/$package"
 curl -fsSL --proto '=https' -o "$work/SHA256SUMS" "$base/SHA256SUMS"
 # The package must match the checksum published beside it.
 (cd "$work" && grep " $package\$" SHA256SUMS | sha256sum -c -)
-# pacman asks which ONNX Runtime build provides onnxruntime.
 sudo pacman -U "$work/$package"