all: update Go to 1.26.1

Bump Go version from 1.26.0 to 1.26.1 across go.mod, Dockerfiles,
and the integration test runner fallback defaults.

Updates #1261

Dockerfile.derper

@@ -1,6 +1,6 @@
 # For testing purposes only
 
-FROM golang:1.26.0-alpine AS build-env
+FROM golang:1.26.1-alpine AS build-env
 
 WORKDIR /go/src
 

Dockerfile.integration

@@ -2,7 +2,7 @@
 # and are in no way endorsed by Headscale's maintainers as an
 # official nor supported release or distribution.
 
-FROM docker.io/golang:1.26.0-trixie AS builder
+FROM docker.io/golang:1.26.1-trixie AS builder
 ARG VERSION=dev
 ENV GOPATH /go
 WORKDIR /go/src/headscale

Dockerfile.tailscale-HEAD

@@ -4,7 +4,7 @@
 # This Dockerfile is more or less lifted from tailscale/tailscale
 # to ensure a similar build process when testing the HEAD of tailscale.
 
-FROM golang:1.26.0-alpine AS build-env
+FROM golang:1.26.1-alpine AS build-env
 
 WORKDIR /go/src
 

cmd/hi/run.go

@@ -76,7 +76,7 @@ func detectGoVersion() string {
 
 	content, err := os.ReadFile(goModPath)
 	if err != nil {
-		return "1.26.0"
+		return "1.26.1"
 	}
 
 	lines := splitLines(string(content))
@@ -91,7 +91,7 @@ func detectGoVersion() string {
 		}
 	}
 
-	return "1.26.0"
+	return "1.26.1"
 }
 
 // splitLines splits a string into lines without using strings.Split.

go.mod

@@ -1,6 +1,6 @@
 module github.com/juanfont/headscale
 
-go 1.26.0
+go 1.26.1
 
 require (
 	github.com/arl/statsviz v0.8.0