chore: update flint to 0.20.4

Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

Author: zeitlinger

.github/renovate.json5

@@ -1,6 +1,7 @@
 {
   $schema: 'https://docs.renovatebot.com/renovate-schema.json',
   extends: [
+    "github>grafana/flint#v0.20.4",
     'config:best-practices',
     'helpers:pinGitHubActionDigestsToSemver',
     'customManagers:githubActionsVersions',

.github/workflows/lint.yml

@@ -0,0 +1,32 @@
+name: Lint
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+          fetch-depth: 0
+
+      - name: Setup mise
+        uses: jdx/mise-action@1648a7812b9aeae629881980618f079932869151 # v4.0.1
+        with:
+          version: v2026.4.18
+          sha256: 6ae2d5f0f23a2f2149bc5d9bf264fe0922a1da843f1903e453516c462b23cc1f
+
+      - name: Lint
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+          GITHUB_HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+        run: mise run lint

.rumdl.toml

@@ -0,0 +1,5 @@
+[MD013]
+enabled = true
+line-length = 120
+code-blocks = false
+tables = false

.yamllint.yml

@@ -0,0 +1,8 @@
+extends: relaxed
+
+rules:
+  document-start: disable
+  line-length:
+    max: 120
+  indentation:
+    spaces: 2

mise.toml

@@ -1,7 +1,18 @@
 [tools]
+
 # Linters
-"github:grafana/flint" = "0.20.3"
+actionlint = "1.7.12"
+"cargo:xmloxide" = "0.4.2"
+"cargo:yaml-lint" = "0.1.0"
+editorconfig-checker = "3.6.1"
+"github:google/google-java-format" = "1.35.0"
+"github:grafana/flint" = "0.20.4"
+"github:pinterest/ktlint" = "1.8.0"
 lychee = "0.23.0"
+"pipx:codespell" = "2.4.2"
+rumdl = "0.1.80"
+shellcheck = "0.11.0"
+shfmt = "3.13.1"
 
 [env]
 FLINT_CONFIG_DIR = ".github/config"