Switch to alpine 3.20.3

Fixes an OpenSSL vulnerability.

release=3.4,3.3
stack=alpine

Author: tarleb

versions.md

@@ -1,8 +1,8 @@
 | pandoc   | tags                          | Alpine | Ubuntu | TeXLive | Lua |
 |----------+-------------------------------+--------+--------+---------+-----|
-| main     | edge                          | 3.20.2 | noble  |         | 5.4 |
-| 3.4      | 3.4.0.0  3.4.0  3.4  3 latest | 3.20.2 | noble  |    2024 | 5.4 |
-| 3.3      | 3.3.0.0  3.3.0  3.3           | 3.20.2 | noble  |    2024 | 5.4 |
+| main     | edge                          | 3.20.3 | noble  |         | 5.4 |
+| 3.4      | 3.4.0.0  3.4.0  3.4  3 latest | 3.20.3 | noble  |    2024 | 5.4 |
+| 3.3      | 3.3.0.0  3.3.0  3.3           | 3.20.3 | noble  |    2024 | 5.4 |
 | 3.2.1    | 3.2.1.0  3.2.1  3.2           | 3.19.3 | noble  |    2024 | 5.4 |
 | 3.1.13   | 3.1.13.0 3.1.13 3.1           | 3.19.3 | noble  |    2024 | 5.4 |
 | 3.1.1    | 3.1.1.0  3.1.1                | 3.16.9 | jammy  |    2022 | 5.4 |