gimp-splash.png embeds date

While working on reproducible builds for openSUSE, I found that our gimp-3.0.0-RC2 package varies in the gimp-splash.png because it embeds the current date+time in the PNG header.

--- old /usr/share/gimp/3.0/images/gimp-splash.png (hex)
+++ new /usr/share/gimp/3.0/images/gimp-splash.png (hex)
@@ -1,6 +1,6 @@
 00000000  89 50 4e 47 0d 0a 1a 0a  00 00 00 0d 49 48 44 52  |.PNG........IHDR|
 00000010  00 00 07 80 00 00 04 38  08 02 00 00 00 67 b1 56  |.......8.....g.V|
-00000020  14 00 00 1c b6 65 58 49  66 49 49 2a 00 08 00 00  |.....eXIfII*....|
+00000020  14 00 00 1c b4 65 58 49  66 49 49 2a 00 08 00 00  |.....eXIfII*....|
 00000030  00 0a 00 00 01 04 00 01  00 00 00 80 07 00 00 01  |................|
 00000040  01 04 00 01 00 00 00 38  04 00 00 02 01 03 00 03  |.......8........|
 00000050  00 00 00 86 00 00 00 0e  01 02 00 12 00 00 00 8c  |................|
@@ -12,8 +12,8 @@
 000000b0  00 08 00 08 00 43 72 65  61 74 65 64 20 77 69 74  |.....Created wit|
 000000c0  68 20 47 49 4d 50 00 2c  01 00 00 01 00 00 00 2c  |h GIMP.,.......,|
 000000d0  01 00 00 01 00 00 00 47  49 4d 50 20 33 2e 30 2e  |.......GIMP 3.0.|
-000000e0  30 2d 52 43 32 00 00 32  30 32 35 3a 30 31 3a 31  |0-RC2..2025:01:1|
-000000f0  37 20 30 38 3a 35 36 3a  32 30 00 02 00 86 92 07  |7 08:56:20......|
+000000e0  30 2d 52 43 32 00 00 32  30 34 31 3a 30 32 3a 31  |0-RC2..2041:02:1|
+000000f0  38 20 32 32 3a 33 38 3a  30 36 00 02 00 86 92 07  |8 22:38:06......|
 00000100  00 19 00 00 00 f0 00 00  00 01 a0 03 00 01 00 00  |................|
 00000110  00 01 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
 00000120  00 43 72 65 61 74 65 64  20 77 69 74 68 20 47 49  |.Created with GI|

This file is probably created by gimp-data/images/export-splash.py as called via gimp-data/images/meson.build