[master] Fix publish date for 1.22.5

[istio-testing]

Manual cherrypick required.

#15713 failed to apply on top of branch "master":

Applying: Fix publish date for 1.22.5
Using index info to reconstruct a base tree...
A	content/en/news/releases/1.22.x/announcing-1.22.5/index.md
Falling back to patching base and 3-way merge...
CONFLICT (modify/delete): content/en/news/releases/1.22.x/announcing-1.22.5/index.md deleted in HEAD and modified in Fix publish date for 1.22.5. Version Fix publish date for 1.22.5 of content/en/news/releases/1.22.x/announcing-1.22.5/index.md left in tree.
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 Fix publish date for 1.22.5
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".