Missing alt text for post author avatar

[t-hamano]

Originally reported at: WordPress/gutenberg#70726

As far as I have checked, there is no alt value in the following two places:

o2/inc/tpl/post-edit.php

Line 5 in 271d520

<img src="{{ data.author.avatar }}" alt="" width="{{ data.avatarSize }}" height="{{ data.avatarSize }}" class="avatar" />

o2/inc/tpl/post.php

Line 5 in 271d520

<img src="{{ data.author.avatar }}" alt="" width="{{ data.author.avatarSize }}" height="{{ data.author.avatarSize }}" class="avatar {{ data.author.modelClass }}" />

[sabernhardt]

Also in the x-post template, the avatar is linked without any alternative text (or alt attribute):

o2/inc/tpl/xpost.php

Lines 2 to 4 in 271d520

	<a href="{{ data.author.url }}" title="{{ data.author.urlTitle }}" class="author-avatar o2-xpost-avatar">
	<img src="{{ data.author.avatar }}" width="{{ data.author.avatarSize }}" height="{{ data.author.avatarSize }}" class="avatar {{ data.author.modelClass }}" />
	</a>