fix: improve Docker image tagging strategy for releases

[hrntknr]

Summary

This PR improves the Docker image tagging strategy to better align with release workflows and reduce unnecessary image builds. The changes ensure that semantic version tags and the 'latest' tag are only applied during official releases, while removing PR-specific tagging that was creating redundant images.

Type of Change

• fix: A bug fix
• feat: A new feature
• docs: Documentation only changes
• style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
• refactor: A code change that neither fixes a bug nor adds a feature
• perf: A code change that improves performance
• test: Adding missing tests or correcting existing tests
• build: Changes that affect the build system or external dependencies
• ci: Changes to our CI configuration files and scripts
• chore: Other changes that don't modify src or test files
• revert: Reverts a previous commit

Changes Made

• Removed PR-specific tagging (type=ref,event=pr,prefix=pr-) to avoid unnecessary image builds on every PR
• Added semantic versioning tags that only trigger on release events:
  • {{version}} (e.g., 1.2.3)
  • {{major}}.{{minor}} (e.g., 1.2)
  • {{major}} (e.g., 1)
• Restricted latest tag to only apply when releases are published instead of on every main branch push
• All version-related tags now only activate when github.event_name == 'release' and github.event.action == 'published'

Benefits

• Reduces Docker registry storage by eliminating redundant PR images
• Provides proper semantic versioning for releases
• Ensures latest tag truly represents the latest stable release
• Maintains branch-based tagging for development builds

Related Issues

[Copilot]

Pull Request Overview

This PR refines the Docker image tagging strategy to optimize for official releases and reduce unnecessary builds. The changes shift from PR-based tagging to semantic versioning patterns that only activate during release events, ensuring better alignment with production workflows.

• Removes PR-specific tagging to eliminate redundant image builds
• Introduces semantic versioning tags (version, major.minor, major) for releases
• Restricts the 'latest' tag to only apply during published releases

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[Copilot]

The enable condition ${{ github.event_name == 'release' && github.event.action == 'published' }} is repeated across multiple lines (44-47). Consider extracting this into a variable or environment variable to improve maintainability and reduce duplication.

Suggested change

	type=semver,pattern={{version}},enable=${{ github.event_name == 'release' && github.event.action == 'published' }}
	type=semver,pattern={{major}}.{{minor}},enable=${{ github.event_name == 'release' && github.event.action == 'published' }}
	type=semver,pattern={{major}},enable=${{ github.event_name == 'release' && github.event.action == 'published' }}
	type=raw,value=latest,enable=${{ github.event_name == 'release' && github.event.action == 'published' }}
	type=semver,pattern={{version}},enable=${{ env.RELEASE_PUBLISHED }}
	type=semver,pattern={{major}}.{{minor}},enable=${{ env.RELEASE_PUBLISHED }}
	type=semver,pattern={{major}},enable=${{ env.RELEASE_PUBLISHED }}
	type=raw,value=latest,enable=${{ env.RELEASE_PUBLISHED }}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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