gh-actions gcc-16: enable running on other forks

set GITHUB_TOKEN to your personal access token, with at least "repo" permissions

curl \
  -X POST \
  -H "Accept: application/vnd.github+json" \
  -H "Authorization: Bearer ${GITHUB_TOKEN}"\
  -H "X-GitHub-Api-Version: 2022-11-28" \
  https://api.github.com/repos/simd-everywhere/simde/dispatches \
  -d '{"event_type":"on-demand-gcc-16","client_payload":{"ref":"MY_BRANCH","repository":"OWNER/REPO"}}'

or

gh api \
  --method POST \
  -H "Accept: application/vnd.github+json" \
  -H "X-GitHub-Api-Version: 2022-11-28" \
  /repos/simd-everywhere/simde/dispatches \
   -f 'event_type=on-demand-gcc-16' -F "client_payload[ref]=MY_BRANCH" -F "client_payload[repository]=OWNER/REPO"

Author: mr-c

.github/workflows/gcc-snapshot.yml

@@ -5,6 +5,8 @@ on:
     branches:
       - 'master'
   workflow_dispatch: {}
+  repository_dispatch:
+    types: [on-demand-gcc-16]
 
 concurrency:
   group: gcc-snapshot-${{ github.event.pull_request.number || github.ref }}
@@ -36,8 +38,15 @@ jobs:
       INTEL_TARGET: ${{ matrix.target }}
     steps:
     - uses: actions/checkout@v6
+      if: ${{ github.event_name != 'repository_dispatch' }}
       with:
         submodules: recursive
+    - uses: actions/checkout@v6
+      if: ${{ github.event_name == 'repository_dispatch' }}
+      with:
+        submodules: recursive
+        repository: ${{ github.event.client_payload.repository }}
+        ref: ${{ github.event.client_payload.ref }}
     - name: CPU Information
       run: cat /proc/cpuinfo
     - name: Install APT Dependencies
@@ -80,8 +89,15 @@ jobs:
       CXXFLAGS: -Wall -Wextra -Werror -march=bdver2
     steps:
     - uses: actions/checkout@v6
+      if: ${{ github.event_name != 'repository_dispatch' }}
+      with:
+        submodules: recursive
+    - uses: actions/checkout@v6
+      if: ${{ github.event_name == 'repository_dispatch' }}
       with:
         submodules: recursive
+        repository: ${{ github.event.client_payload.repository }}
+        ref: ${{ github.event.client_payload.ref }}
     - name: CPU Information
       run: cat /proc/cpuinfo
     - name: Install APT Dependencies
@@ -117,8 +133,15 @@ jobs:
       CXXFLAGS: -march=native -Wall -Wextra -Werror
     steps:
     - uses: actions/checkout@v6
+      if: ${{ github.event_name != 'repository_dispatch' }}
       with:
         submodules: recursive
+    - uses: actions/checkout@v6
+      if: ${{ github.event_name == 'repository_dispatch' }}
+      with:
+        submodules: recursive
+        repository: ${{ github.event.client_payload.repository }}
+        ref: ${{ github.event.client_payload.ref }}
     - id: cpu
       name: CPU Information
       run: |
@@ -168,8 +191,15 @@ jobs:
       CXXFLAGS: ${{ matrix.arch_flags }} -march=native -Wall -Wextra -Werror
     steps:
     - uses: actions/checkout@v6
+      if: ${{ github.event_name != 'repository_dispatch' }}
+      with:
+        submodules: recursive
+    - uses: actions/checkout@v6
+      if: ${{ github.event_name == 'repository_dispatch' }}
       with:
         submodules: recursive
+        repository: ${{ github.event.client_payload.repository }}
+        ref: ${{ github.event.client_payload.ref }}
     - id: cpu
       name: CPU Information
       run: |
@@ -265,8 +295,15 @@ jobs:
     runs-on: ${{ matrix.distro }}
     steps:
     - uses: actions/checkout@v6
+      if: ${{ github.event_name != 'repository_dispatch' }}
+      with:
+        submodules: recursive
+    - uses: actions/checkout@v6
+      if: ${{ github.event_name == 'repository_dispatch' }}
       with:
         submodules: recursive
+        repository: ${{ github.event.client_payload.repository }}
+        ref: ${{ github.event.client_payload.ref }}
     - name: CPU Information
       run: cat /proc/cpuinfo
     - name: Install APT Dependencies