Fix: Time to Read block showing "this block has encountered an error" -

#61459 (#61614)

* Fix the issue related to replace method for undefined, replace it with optional chaining so undefined can be prevented

* Revert the optional chaining commit for the wordcount pacakges

* Pass empty string if we get content undefined in time to read block

Unlinked contributors: bradhogan.

Co-authored-by: hbhalodia <hbhalodia@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>

packages/block-library/src/post-time-to-read/edit.js

@@ -66,7 +66,7 @@ function PostTimeToReadEdit( { attributes, setAttributes, context } ) {
 		const minutesToRead = Math.max(
 			1,
 			Math.round(
-				wordCount( content, wordCountType ) / AVERAGE_READING_RATE
+				wordCount( content || '', wordCountType ) / AVERAGE_READING_RATE
 			)
 		);