chore(deps): update go module directive to v1.26.4

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

go.mod

@@ -4,7 +4,7 @@
 
 module itiquette/git-provider-sync
 
-go 1.24.2
+go 1.26.4
 
 require (
 	code.gitea.io/sdk/gitea v0.21.0