Improve version determination in publish workflow

[lupodevelop]

Update the GitHub Actions workflow to determine the version from the tag if available, or fall back to the version in gleam.toml when triggered by a merged PR. This makes the workflow more robust for different trigger scenarios.

[Copilot]

Pull Request Overview

This PR improves the robustness of the publish workflow by adding conditional version determination logic. The workflow now checks if it's triggered by a tag push and extracts the version from the tag, or falls back to reading the version from gleam.toml when triggered by a merged PR.

Key Changes

• Added conditional logic to check if the workflow is triggered by a tag push
• Implemented fallback to read version from gleam.toml when no tag is present
• Updated step name from "Determine version from tag" to "Determine version" to reflect the broader functionality

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[Copilot]

The escaped double quote in the character class [^\"]+ is unnecessary and incorrect. Since the sed expression is enclosed in single quotes, the backslash before the double quote is treated literally. This should be [^"]+ instead. While this may work in practice, it's technically incorrect regex syntax.

[Copilot]

The || true at the end of this line suppresses errors and could result in an empty VERSION variable if grep or sed fails. This undermines the set -euo pipefail on line 78. Consider removing || true to allow the step to fail properly if the version cannot be determined, or add explicit validation after this line to check if VERSION is non-empty and fail with a clear error message if it's not.

Suggested change

	VERSION=$(grep '^version' gleam.toml | sed -E 's/.*= *"([^\"]+)".*/\1/') || true
	VERSION=$(grep '^version' gleam.toml | sed -E 's/.*= *"([^\"]+)".*/\1/')
	if [ -z "${VERSION}" ]; then
	echo "Error: Could not determine version from gleam.toml" >&2
	exit 1
	fi