refactor(ci): Enhance CHANGELOG management to remove duplicate entries

- Implement function to remove duplicate lines within each CHANGELOG
entry
- Apply deduplication to existing entries and new updates
- Preserve original order of items after deduplication
- Maintain Mountain Time conversion and single Full Changelog link per
entry

This update improves the quality and readability of our CHANGELOG by
eliminating redundant information. It addresses the issue of duplicate
items within entries, ensuring a cleaner and more concise project
history.
The change affects both existing entries and future updates, providing
a consistent and streamlined changelog format moving forward.

.github/workflows/release.yml

@@ -140,6 +140,10 @@ jobs:
             echo
           }
 
+          remove_duplicates() {
+            echo "$1" | awk '!seen[$0]++'
+          }
+
           echo "# Changelog" > temp_changelog.md
           echo >> temp_changelog.md
 
@@ -163,6 +167,9 @@ jobs:
               
               # Remove all existing Full Changelog links
               content=$(echo "$content" | sed '/^\[Full Changelog\]/d')
+
+              # Remove duplicate lines
+              content=$(remove_duplicates "$content")
               
               # Trim leading and trailing whitespace
               content=$(echo "$content" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')