feat(man): replace hardcoded version by version variable

Signed-off-by: Sandro-Alessio Gierens <sandro@gierens.de>

man/eza.1.md

@@ -1,4 +1,4 @@
-% eza(1) v0.9.0
+% eza(1) $version
 
 <!-- This is the eza(1) man page, written in Markdown. -->
 <!-- To generate the roff version, run `just man`, -->

man/eza_colors.5.md

@@ -1,4 +1,4 @@
-% eza_colors(5) v0.9.0
+% eza_colors(5) $version
 
 <!-- This is the eza_colors(5) man page, written in Markdown. -->
 <!-- To generate the roff version, run `just man`, -->