fix(copilot-cli): use semver sort for prerelease tag resolution

[Copilot]

The prerelease channel resolves the install candidate via git ls-remote --tags | tail -1, which sorts alphabetically. This picks v1.0.9 over v1.0.45 because "9" > "4" lexicographically.

Fix: Replace the alphabetic tail with a version-sorted pipeline:

git ls-remote --tags https://github.com/github/copilot-cli \
  | awk '{print $2}' | sed 's|refs/tags/||' \
  | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+(-[0-9]+)?' \
  | sort -V | tail -n1

• Filter to well-formed vX.Y.Z[-N] tags (excludes stray refs)
• Sort with sort -V (version sort) instead of relying on git's lexicographic order
• Bump feature version 1.1.2 → 1.1.3