update metadata for release 0.19.0 (#372)

* freeze change log

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

CHANGES.rst

@@ -1,4 +1,9 @@
-0.18.1 (unreleased)
+0.19.1 (unreleased)
+-------------------
+
+-
+
+0.19.0 (2024-02-09)
 -------------------
 
 - Added streamlined Level 3 Mosaic metadata schemas. [#334]