bump Go to 1.26, golangci-lint to 2.9.0, goreleaser to 2.13.3

Author: umputun

CLAUDE.md

@@ -54,4 +54,4 @@ Go build image version is controlled by env vars in `build.go/Dockerfile`:
 - `GOLANGCI` - golangci-lint version
 - `GORELEASER` - goreleaser version
 - `GOVERALLS`, `STATIK` - other tool versions
-- Base Go version in FROM directive (e.g., `golang:1.25-alpine`)
+- Base Go version in FROM directive (e.g., `golang:1.26-alpine`)

build.go/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.25-alpine
+FROM golang:1.26-alpine
 
 LABEL org.opencontainers.image.authors="Umputun <umputun@gmail.com>"
 # enables automatic changelog generation by tools like Dependabot
@@ -8,9 +8,9 @@ ENV \
     TIME_ZONE=America/Chicago   \
     CGO_ENABLED=0               \
     GOVERALLS=0.0.12            \
-    GOLANGCI=2.7.2              \
+    GOLANGCI=2.9.0              \
     STATIK=0.1.7                \
-    GORELEASER=2.13.1
+    GORELEASER=2.13.3
 
 # install gcc in order to be able to go test package with -race
 RUN apk --no-cache add gcc libc-dev