[KYUUBI apache#5432] Fix typo in README.md

## Description:
This Pull Request fixes a typographical error in the README.md file.

## Changes Made:
"e.t.c." has been changed to "etc." for the correct abbreviation.

## Additional Information:
This fix is not related to any existing issue. It's a minor typo that I noticed while reviewing the README.

Thank you for considering this contribution.

Closes apache#5431 from omimakhare/patch-1.

Closes apache#5432

b5c1aa6 [OMKAR MAKHARE] Update README.md

Lead-authored-by: Omkar Makhare <omimakhare11@gmail.com>
Co-authored-by: OMKAR MAKHARE <114830033+omimakhare@users.noreply.github.com>
Signed-off-by: Cheng Pan <chengpan@apache.org>

Author: omimakhare

README.md

@@ -68,7 +68,7 @@ In typical big data production environments with Kyuubi, there should be system
 - System administrators: A small group consists of Spark experts responsible for Kyuubi deployment, configuration, and tuning.
 - End-users: Focus on business data of their own, not where it stores, how it computes.
 
-Additionally, the Kyuubi community will continuously optimize the whole system with various features, such as History-Based Optimizer, Auto-tuning, Materialized View, SQL Dialects, Functions, e.t.c.
+Additionally, the Kyuubi community will continuously optimize the whole system with various features, such as History-Based Optimizer, Auto-tuning, Materialized View, SQL Dialects, Functions, etc.
 
 ### Usage scenarios