go.mod: don't enforce go1.23.5 patch version

commit 08fb086 added a go.mod, but
set the minimum required version to the patch version.

Generally, go versions in go.mod, like other dependencies, follow
"MVS" (minimum version selection) conventions, and specify the lowest
possible / supported minimum version. Keeping the version low avoids
unnecessary code churn in projects using this module.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

go.mod

@@ -1,6 +1,6 @@
 module github.com/fluent/fluent-logger-golang
 
-go 1.23.5
+go 1.23.0
 
 require github.com/tinylib/msgp v1.3.0