Sort CHANGELOG.md entries in reverse chronological order

[Copilot]

Description

Reordered all 92 release entries in CHANGELOG.md from newest (2025-11-15) to oldest (2019-08-27). Previously, entries were inconsistently ordered with newer releases appearing after older ones.

Changes:

• Sorted release sections by date in descending order
• Added clarifying note at top: "Releases are sorted in reverse chronological order (newest first)"
• Preserved all content and formatting within each release section

Before: Mixed ordering (e.g., 6.1.3 from 2025-11-12 appeared after 7.0.0-preview1 from 2025-09-12)

After: Consistent descending date order (6.0.4 from 2025-11-15 at top, 1.0.19239.1 from 2019-08-27 at bottom)

Issues

Resolves the requirement to organize CHANGELOG.md in a chronologically consistent manner for improved readability.

Testing

Automated verification:

• Date order validation confirms all 92 releases are in descending chronological sequence
• Content integrity verified through diff analysis (398 insertions, 395 deletions - line reordering only)

Manual verification:

• Spot-checked header note insertion
• Verified newest release (6.0.4) at top
• Verified oldest release (1.0.19239.1) at bottom
• Confirmed release section content unchanged

Guidelines

• Reviewed contribution guidelines
• Changes preserve all existing content
• Documentation-only change requires no code tests

Original prompt

Resort all release entries in the CHANGELOG.md file (https://github.com/dotnet/SqlClient/blob/main/CHANGELOG.md) so that release sections appear in reverse chronological order (newest release/date at the top, oldest at the bottom). Do not alter the text within each release entry. Add a clear note at the top indicating that releases are sorted newest to oldest. Preserve the changelog formatting. Commit the changes to a new branch and open a pull request on dotnet/SqlClient.

This pull request was created as a result of the following prompt from Copilot chat.

Resort all release entries in the CHANGELOG.md file (https://github.com/dotnet/SqlClient/blob/main/CHANGELOG.md) so that release sections appear in reverse chronological order (newest release/date at the top, oldest at the bottom). Do not alter the text within each release entry. Add a clear note at the top indicating that releases are sorted newest to oldest. Preserve the changelog formatting. Commit the changes to a new branch and open a pull request on dotnet/SqlClient.

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[Copilot]

Pull Request Overview

This PR reorganizes the CHANGELOG.md file to display all 92 release entries in reverse chronological order (newest to oldest), improving readability and maintainability.

Key Changes:

• Added a clarifying note indicating releases are sorted newest first
• Reordered all release sections by date in descending order (2025-11-15 to 2019-08-27)
• Preserved all original content and formatting within each release section

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.82%. Comparing base (37dde3f) to head (a950b22).
⚠️ Report is 6 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #3783       +/-   ##
===========================================
+ Coverage   76.59%   90.82%   +14.22%     
===========================================
  Files         274        6      -268     
  Lines       43395      316    -43079     
===========================================
- Hits        33240      287    -32953     
+ Misses      10155       29    -10126     

Flag	Coverage Δ
addons	90.82% <ø> (ø)
netcore	?
netfx	?

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