docs(changelog): Reduce duplication

CHANGELOG.rst

@@ -15,10 +15,8 @@ Unreleased
 1.7.0 - Jan 3, 2023
 -------------------
 
-* Add Python 3.11 support.
-* Add Python 3.10 support.
-* Drop Python 3.6 support (end-of-life was December 23, 2021).
-* Drop Python 2.7 support (end-of-life was January 1, 2020).
+* Add Python 3.10 and 3.11 support.
+* Drop support for Python 2.7 (EOL 2020-01-01), 3.6 (2021-12-23).
 
 1.6.3 - July 15, 2021
 ---------------------
@@ -39,8 +37,7 @@ Unreleased
 * fix: Aggregations return ``None`` if all values are ``None``, instead of raising an error. Note that ``Sum``, ``MaxLength`` and ``MaxPrecision`` continue to return ``0`` if all values are ``None``. (#706)
 * fix: Ensure files are closed when errors occur. (#734)
 * build: Make PyICU an optional dependency.
-* Drop Python 3.5 support (end-of-life was September 13, 2020).
-* Drop Python 3.4 support (end-of-life was March 18, 2019).
+* Drop support for Python 3.4 (2019-03-18), 3.5 (2020-09-13).
 
 1.6.2 - March 10, 2021
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