fix(button): don't needlessly overwrite title

[maxpatiiuk]

Related Issue: #8417

Summary

In my application I set title attribute on the <calcite-button>, but it wasn't being displayed because the shadow DOM's <button> had an empty title attribute (title="") which was overwriting the title set on the calcite-button.

Reproduction:

1. Codepen example
2. Hover over the button - no tooltip is shown
3. Remove the "title" attribute from the <button>, and tooltip is visible

Video reproduction:

out.mp4

[maxpatiiuk]

@benelan there may be something wrong with the pull bot. both of my PRs are marked as "merged" (this one, and #8385), despite changes not being merged
the bot seems to force-push, which overwrites the commits I have

[benelan]

Sorry I thought I responded to this! I'm pretty sure this is something on your end. I don't think we can do anything to push push to your fork without you giving us write privilege. Did you install GitHub's Pull App? I think you can check in your account's Application settings.

[maxpatiiuk]

You are correct - I forgot that I even had that enabled.
Thank you for the information)
Opened a new pull request - #8491