ci: pass NIX_CONFIG with GitHub token into all test containers

- Add NIX_CONFIG with GitHub access token to all CI test workflows
- Export NIX_CONFIG in Makefile for propagation to test scripts
- Forward NIX_CONFIG explicitly into all docker run invocations
- Prevent GitHub API rate limit errors during Nix-based tests

https://chatgpt.com/share/69432655-a948-800f-8c0d-353921cdf644

.github/workflows/test-e2e.yml

@@ -11,7 +11,9 @@ jobs:
       fail-fast: false
       matrix:
         distro: [arch, debian, ubuntu, fedora, centos]
-
+    env:
+      NIX_CONFIG: |
+        access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

.github/workflows/test-env-nix.yml

@@ -12,7 +12,9 @@ jobs:
       fail-fast: false
       matrix:
         distro: [arch, debian, ubuntu, fedora, centos]
-
+    env:
+      NIX_CONFIG: |
+        access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

.github/workflows/test-env-virtual.yml

@@ -11,7 +11,9 @@ jobs:
       fail-fast: false
       matrix:
         distro: [arch, debian, ubuntu, fedora, centos]
-
+    env:
+      NIX_CONFIG: |
+        access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

.github/workflows/test-integration.yml

@@ -7,7 +7,9 @@ jobs:
   test-integration:
     runs-on: ubuntu-latest
     timeout-minutes: 30
-
+    env:
+      NIX_CONFIG: |
+        access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

.github/workflows/test-unit.yml

@@ -7,7 +7,9 @@ jobs:
   test-unit:
     runs-on: ubuntu-latest
     timeout-minutes: 30
-
+    env:
+      NIX_CONFIG: |
+        access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

.github/workflows/test-virgin-root.yml

@@ -11,7 +11,9 @@ jobs:
       fail-fast: false
       matrix:
         distro: [arch, debian, ubuntu, fedora, centos]
-
+    env:
+      NIX_CONFIG: |
+        access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -19,13 +21,11 @@ jobs:
       - name: Show Docker version
         run: docker version
 
-      # 🔹 BUILD virgin image if missing
       - name: Build virgin container (${{ matrix.distro }})
         run: |
           set -euo pipefail
           PKGMGR_DISTRO="${{ matrix.distro }}" make build-missing-virgin
 
-      # 🔹 RUN test inside virgin image
       - name: Virgin ${{ matrix.distro }} pkgmgr test (root)
         run: |
           set -euo pipefail
@@ -34,6 +34,7 @@ jobs:
             -v "$PWD":/opt/src/pkgmgr \
             -v pkgmgr_repos:/root/Repositories \
             -v pkgmgr_pip_cache:/root/.cache/pip \
+            -e NIX_CONFIG="${NIX_CONFIG}" \
             -w /opt/src/pkgmgr \
             "pkgmgr-${{ matrix.distro }}-virgin" \
             bash -lc '

.github/workflows/test-virgin-user.yml

@@ -11,7 +11,9 @@ jobs:
       fail-fast: false
       matrix:
         distro: [arch, debian, ubuntu, fedora, centos]
-
+    env:
+      NIX_CONFIG: |
+        access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -19,19 +21,18 @@ jobs:
       - name: Show Docker version
         run: docker version
 
-      # 🔹 BUILD virgin image if missing
       - name: Build virgin container (${{ matrix.distro }})
         run: |
           set -euo pipefail
           PKGMGR_DISTRO="${{ matrix.distro }}" make build-missing-virgin
 
-      # 🔹 RUN test inside virgin image as non-root
       - name: Virgin ${{ matrix.distro }} pkgmgr test (user)
         run: |
           set -euo pipefail
 
           docker run --rm \
             -v "$PWD":/opt/src/pkgmgr \
+            -e NIX_CONFIG="${NIX_CONFIG}" \
             -w /opt/src/pkgmgr \
             "pkgmgr-${{ matrix.distro }}-virgin" \
             bash -lc '