Replace OS detection with package manager detection in install scripts

[Copilot]

Install scripts were detecting the OS via /etc/os-release to infer the package manager, rather than detecting the package manager directly. This couples logic unnecessarily to OS identity rather than actual available tooling.

Changes

• microsoft-git, devtool, artifacts-helper, go install scripts: Removed . /etc/os-release and replaced ${ID} = "mariner" conditionals with command -v tdnf >/dev/null 2>&1 checks — matching the pattern already used in docfx/install.sh
• Version bumps: Incremented patch version for each modified feature

Before

. /etc/os-release
if [ "${ID}" = "mariner" ]; then
    tdnf install -y curl ca-certificates
else
    check_packages curl ca-certificates
fi

After

if command -v tdnf >/dev/null 2>&1; then
    tdnf install -y curl ca-certificates
else
    check_packages curl ca-certificates
fi

Feature	Version
microsoft-git	1.0.8 → 1.0.9
devtool	1.0.3 → 1.0.4
artifacts-helper	3.0.5 → 3.0.6
go	1.2.0 → 1.2.1

external-repository has no package manager logic; docfx was already compliant — neither required changes.