fix(go): build with Go 1.26.5 for aligned cgo frames, safe on arm32

Fixes the random gobind crash 'bulkBarrierPreWrite: unaligned arguments'
(golang/go#46893; cgo aligns exported-function argument frames since
1.26.0). The earlier 1.26 rollback (cdc58367) was the arm32 SIGSYS from
probing futex_time64 under seccomp on Android <=10 — fixed in 1.26.3 by
gating time64 syscalls on kernel >= 5.1 instead of probing (verified in
the 1.26.5 runtime source, which names Android 8-10 explicitly).
go directive carries the full patch version so gomobile's synthesized
bind module picks the same toolchain.

.github/workflows/release.yml

@@ -70,7 +70,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v6
         with:
-          go-version: "1.25.9"
+          go-version: "1.26.5"
           cache-dependency-path: go_backend/go.sum
 
       # Cache Gradle for faster builds
@@ -198,7 +198,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v6
         with:
-          go-version: "1.25.9"
+          go-version: "1.26.5"
           cache-dependency-path: go_backend/go.sum
 
       # Cache CocoaPods