feat(workflows): add concurrency control to prevent duplicate runs

Added concurrency groups with cancel-in-progress to validate.yml, lint.yml,
and auto-tag.yml workflows.

This ensures that when multiple commits are pushed quickly:
- Only the latest validation/lint run continues
- Older runs are automatically cancelled
- Saves CI minutes and provides faster feedback

Release workflow intentionally excluded (each tag is unique).

Impact: More efficient CI usage, faster feedback on rapid commits.

.github/workflows/auto-tag.yml

@@ -10,6 +10,10 @@ on:
 permissions:
   contents: write
 
+concurrency:
+  group: ${{ github.workflow }}
+  cancel-in-progress: true
+
 jobs:
   check-and-tag:
     name: Check and create version tag

.github/workflows/lint.yml

@@ -10,6 +10,10 @@ on:
 
 permissions: {}
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   ruff:
     name: "Ruff"

.github/workflows/validate.yml

@@ -13,6 +13,10 @@ on:
 
 permissions: {}
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   hassfest: # https://developers.home-assistant.io/blog/2020/04/16/hassfest
     name: Hassfest validation