chore(deps): update dependency go to v1.26.3 (#255)

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

Author: renovate[bot]

go.mod

@@ -2,7 +2,7 @@ module github.com/koki-develop/gat
 
 go 1.25.0
 
-toolchain go1.25.5
+toolchain go1.26.3
 
 require (
 	github.com/alecthomas/chroma/v2 v2.21.1

mise.toml

@@ -1,5 +1,5 @@
 [tools]
-go = "1.25.5"
+go = "1.26.3"
 
 "go:github.com/golangci/golangci-lint/v2/cmd/golangci-lint" = "2.7.2"
 "go:github.com/charmbracelet/vhs" = "0.9.0"