IVT: Trap case where limited platforms mean no zip or no tgz exist in release

[sxa]

Fixes https://github.com/adoptium/temurin/issues/28#issuecomment-2085303993

Recommend reviewing ignoring whitespace as this is a simple change but adds indents due to the if section.

[sxa]

Also fixes https://github.com/adoptium/temurin-build/issues/3801

I would normally have done this in a separate PR but I needed to test it all together to do it properly and this has only had one approval so far, therefore requesting @karianna to re-approve.

[karianna]

In /github/workspace/tooling/release_download_test.sh line 214: for A in ls -1d OpenJDK*.tar.gz OpenJDK*.zip *.msi *.pkg *sbom*[0-9].json; do ^-- SC2045 (warning): Iterating over ls output is fragile. Use globs. ^-- SC2006 (style): Use $(...) notation instead of legacy backticks .... ^-- SC2035 (info): Use ./glob or -- glob so names with dashes won't become options. ^-- SC2035 (info): Use ./glob or -- glob so names with dashes won't become options. ^-- SC2035 (info): Use ./glob or -- glob so names with dashes won't become options.