Reword & remove unreleased features

Author: rzats

src/client/packaging/pypi/CHANGELOG.md

@@ -3,25 +3,13 @@
 All notable future changes to the `delphi_epidata` python client will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
-## [4.1.21] - TBD
-
-### Includes
-- https://github.com/cmu-delphi/delphi-epidata/pull/1418
-- https://github.com/cmu-delphi/delphi-epidata/pull/1436
-
-### Added
-- Adds two debug flags: `debug` logs info about HTTP requests and responses; whereas `sandbox` prevents any HTTP requests from actually executing, allowing for tests that do not incur server load.
-
-### Changed
-- Updates internal version detection to use `bumpversion`.
-
 ## [4.1.17] - 2024-01-30
 
 ### Includes
 - https://github.com/cmu-delphi/delphi-epidata/pull/1363
 
-### Removed
-- Removes uses of setuptools' deprecated pkg_resources library - these are replaced by the native importlib.metadata library.
+### Changed
+- Replaced use of deprecated setuptools' `pkg_resources` library with the native `importlib.metadata` library.
 
 ## [4.1.13] - 2023-11-04
 
@@ -33,7 +21,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 - Appends a trailing slash to URLs requested by the Python client, which should prevent an automatic redirect and an extra request to the server.
 
 ### Removed
-- Mutes the covidcast_nowcast endpoint & removes unnecessary code that is related to this endpoint.
+- Removed the `covidcast_nowcast()` method, as the associated API endpoint is no longer available.
 
 ## [4.1.11] - 2023-10-12