feat: add configurable chart-path input

Allow users to specify a custom path to Chart.yaml via the chart-path
input. The add-annotations.sh script reads the CHART_FILE environment
variable with a fallback to "Chart.yaml" for standalone usage.

Co-authored-by: Copilot <copilot@github.com>

install-yq.sh

@@ -78,5 +78,5 @@ echo "INFO: Installed ${yq_installed_version} in ${bin_path}"
 
 # Ensure yq is in PATH for subsequent steps
 if [[ -n "${GITHUB_PATH:-}" ]]; then
-  echo "$(dirname "${bin_path}")" >> "${GITHUB_PATH}"
+  "$(dirname "${bin_path}")" >> "${GITHUB_PATH}"
 fi