fix(ci): update LLGo to v1.0.7 #54

The CI workflow currently builds LLGo from 6fc2ef150f95d8b9331433f325fcb1b6ee5ad4e4, a development commit from 2026-08-28 between v1.0.0 and v1.0.1. Update the CI toolchain to the released LLGo v1.0.7.

Failure motivating the update

PR #45 fails in the Ubuntu native-binding test job:

TestNativeLibcLayouts/native_types/X__ComparFnT/size
Go layout = 16, C headers = 8

X__ComparFnT is a C comparison-function pointer alias marked // llgo:type C. The old compiler's size calculation unwraps the alias without checking its C calling convention, then adds an extra pointer as though it were a Go closure. All 214 new C function symbol-link checks pass; the failing assertion detects the callback alias size mismatch. The macOS job passes.

The verified v1.0.7 tag resolves to 53acb9a7ceb5658ad79f2cf1e03d0cc17fecfee6 and contains the C callback alias fixes; the fix commit is an ancestor of the release.

Requested update

• Change the LLGo checkout ref in .github/workflows/go.yml to v1.0.7, separately from the generated libc binding changes.
• Check the source-build recipe against the release: v1.0.7 declares Go 1.27.0 and github.com/xgo-dev/llvm v0.10.1, while the current workflow forcibly overrides the LLVM Go binding to v0.9.8.
• Run the existing Ubuntu and macOS LLGo jobs with the updated toolchain and rerun PR feat(c): add libc bindings with native ABI coverage #45, keeping the native callback size assertion intact.