Fix CI/CD builds: upgrade deprecated runners and use native ARM64

Updates GitHub Actions workflows to fix deprecated runner issues and
improve ARM64 builds:

Release workflow:
- Fix x86_64 Linux: ubuntu-20.04 → ubuntu-latest (20.04 is deprecated)
- Use native ARM64 runner: ubuntu-24.04-arm instead of cross-compilation
- Remove gcc-aarch64-linux-gnu cross-compiler dependency
- Build natively on ARM for better SIMD support and reliability

Test workflow:
- Fix x86_64 Linux: ubuntu-20.04 → ubuntu-latest (20.04 is deprecated)

Benefits:
- Prevents build failures from deprecated runners
- Native ARM builds are more reliable and faster
- Better testing of ARM NEON SIMD optimizations
- Easier debugging if ARM-specific issues arise

Merged from upstream PR asg017#228 by anuraaga.

Co-Authored-By: Anuraag (Rag) Agrawal <[email protected]>

Author: vlasky

.github/workflows/release.yaml

@@ -6,7 +6,7 @@ permissions:
   contents: read
 jobs:
   build-linux-x86_64-extension:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - run: ./scripts/vendor.sh
@@ -55,13 +55,12 @@ jobs:
           name: sqlite-vec-windows-x86_64-extension
           path: dist/*
   build-linux-aarch64-extension:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04-arm
     steps:
       - uses: actions/checkout@v4
-      - run: sudo apt-get install gcc-aarch64-linux-gnu
       - run: ./scripts/vendor.sh
       - run: make sqlite-vec.h
-      - run: make CC=aarch64-linux-gnu-gcc loadable static
+      - run: make loadable static
       - uses: actions/upload-artifact@v4
         with:
           name: sqlite-vec-linux-aarch64-extension

.github/workflows/test.yaml

@@ -7,7 +7,7 @@ permissions:
   contents: read
 jobs:
   build-linux-x86_64-extension:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: astral-sh/setup-uv@v3