ci: don't depend on toolchain version

43890be increased the go directive to 1.26.0, which made go mod tidy
remove the `toolchain go1.26.0` line. This caused the Makefile to
resolve the build image to `gotify/build:null-x`.

Author: jmattheis

.github/workflows/build.yml

@@ -7,13 +7,13 @@ jobs:
     # Run on push for branches in this repo, and on pull_request only for forks.
     if: github.event_name == 'push' || (github.event_name == 'pull_request' && github.repository != github.event.pull_request.head.repo.full_name)
     steps:
+      - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: 1.26.x
+          go-version-file: GO_VERSION
       - uses: actions/setup-node@v7
         with:
           node-version: '24'
-      - uses: actions/checkout@v7
       - run: (cd ui && yarn)
       - run: make build-js
       - uses: golangci/golangci-lint-action@v9

Makefile

@@ -2,7 +2,7 @@ LICENSE_DIR=./licenses/
 BUILD_DIR=./build
 DOCKER_DIR=./docker/
 SHELL := /bin/bash
-GO_VERSION=$(shell go mod edit -json | jq -r .Toolchain | sed -e 's/go//')
+GO_VERSION=$(shell cat GO_VERSION)
 DOCKER_BUILD_IMAGE=docker.io/gotify/build
 DOCKER_WORKDIR=/proj
 DOCKER_RUN=docker run --rm -e LD_FLAGS="$$LD_FLAGS" -v "$$PWD/.:${DOCKER_WORKDIR}" -v "`go env GOPATH`/pkg/mod/.:/go/pkg/mod:ro" -w ${DOCKER_WORKDIR}

renovate.json

@@ -32,21 +32,6 @@
       "autoReplaceStringTemplate": "{{{newValue}}}",
       "datasourceTemplate": "docker",
       "versioningTemplate": "docker"
-    },
-    {
-      "customType": "regex",
-      "managerFilePatterns": [
-        "/^go.mod$/"
-      ],
-      "depTypeTemplate": "language",
-      "matchStrings": [
-        "toolchain go(?<currentValue>[0-9.]+)\\n"
-      ],
-      "extractVersionTemplate": "^(?<version>.+)-linux-amd64$",
-      "depNameTemplate": "docker.io/gotify/build",
-      "autoReplaceStringTemplate": "toolchain go{{{newValue}}}\n",
-      "datasourceTemplate": "docker",
-      "versioningTemplate": "docker"
     }
   ],
   "ignoreDeps": [