Fix CI deadlock: remove concurrency from reusable workflows

Reusable workflows inherit concurrency context from parent workflows.
Having concurrency groups in both causes a deadlock.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: JAORMX

.github/workflows/build.yml

@@ -6,10 +6,6 @@ on:
 permissions:
   contents: read
 
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
-
 jobs:
 
   build:

.github/workflows/lint.yml

@@ -6,10 +6,6 @@ on:
 permissions:
   contents: read
 
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
-
 jobs:
   lint-go:
     name: Lint Go

.github/workflows/test.yml

@@ -6,10 +6,6 @@ on:
 permissions:
   contents: read
 
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
-
 jobs:
   test:
     name: Test