astro/mepo: update to 1.3.3 after b2b3906286ed

mepo-1.2.1/build.zig:14:27: error: no field named 'path' in union 'Build.LazyPath'
/usr/local/lib/zig/std/Build.zig:2171:22: note: union declared here

PR: 279604
Changes: https://git.sr.ht/~mil/mepo/refs/1.3.0
Changes: https://git.sr.ht/~mil/mepo/refs/1.3.1
Changes: https://git.sr.ht/~mil/mepo/refs/1.3.2
Changes: https://git.sr.ht/~mil/mepo/refs/1.3.3
Reported by: Repology