Add PR #1226 to changelog.

Author: tmiw

USER_MANUAL.md

@@ -887,6 +887,7 @@ LDPC | Low Density Parity Check Codes - a family of powerful FEC codes
     * FreeDV Reporter: Use ItemsAdded/ItemsDeleted instead of Cleared() for performance. (PR #1212)
 3. Build system:
     * Windows/macOS: Update Python to 3.14.3. (PR #1221)
+    * Update Hamlib to 4.7.0. (PR #1226)
 4. Documentation:
     * Update README instructions to reflect current Windows build steps. (PR #1232)