fix(tag-action): strip prefix from pre_tag before semver operation

[mashmalko]

Summary of changes

Fix semver parsing error when bumping prerelease tags on feature branches with tag prefixes.

Problem:
When bumping an existing prerelease tag on feature branches, the script was passing pre_tag (e.g., "customprefix0.3.3-feature-super.1") directly to semver -i prerelease, which failed because semver cannot parse version strings with non-standard prefixes like "customprefix".

Solution:
Strip the tag prefix from pre_tag before passing it to semver, matching the existing pattern used for current_tag (lines 171-176). The prefix is then added back to the semver result, ensuring the final tag maintains the correct format.

Changes:

• Added prefix stripping logic for pre_tag (lines 216-222), mirroring the current_tag handling
• Updated semver command on line 226 to use current_pre_tag (without prefix) instead of pre_tag (with prefix)

Example:

• Before: semver -i prerelease "customprefix0.3.3-feature-super.1" --preid "feature-super" ❌ (fails)
• After: semver -i prerelease "0.3.3-feature-super.1" --preid "feature-super" ✅ (works, then prefix added back)

Breaking Changes

Do any of the included changes break current behaviour or configuration?

NO

This is a bug fix that maintains backward compatibility. The behavior for:

• Main/release branches: Unchanged (prerelease block is skipped)
• Feature branches without existing prerelease tags: Unchanged (goes to else branch, creates new .0 tag)
• Feature branches with existing prerelease tags: Fixed (now correctly bumps prerelease number instead of failing)

How changes have been tested

• Logic verification: Traced through the code flow for both main and feature branch scenarios
• Edge cases verified:
  • Empty tagPrefix: Handled correctly (no prefix stripping needed)
  • Empty pre_tag: Handled correctly (condition evaluates to false, goes to else branch)
  • Regex condition: Still uses original pre_tag with prefix (correct, since $new also has prefix)
• Pattern consistency: Matches existing current_tag prefix stripping pattern (lines 171-176)
• Manual testing: Simulated the fix with example values to verify semver command format

List any unknowns

• None identified. The fix follows the exact same pattern already used successfully for current_tag prefix stripping, ensuring consistency and reliability.