.github/workflows: add tests for Linux arm64

Run env GOOS=linux GOARCH=arm64 CGO_ENABLED=0 go test -c -o=purego-test-nocgo -shuffle=on -v -count=10 -v .
  env GOOS=linux GOARCH=arm64 CGO_ENABLED=0 go test -c -o=purego-test-nocgo -shuffle=on -v -count=10 -v .
  env QEMU_LD_PREFIX=/usr/aarch64-linux-gnu qemu-aarch64 ./purego-test-nocgo
  env GOOS=linux GOARCH=arm64 CGO_ENABLED=1 go test -c -o=purego-test-cgo -shuffle=on -v -count=10 -v .
  env QEMU_LD_PREFIX=/usr/aarch64-linux-gnu qemu-aarch64 ./purego-test-cgo
  shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
--- FAIL: TestCallGoFromSharedLib (0.08s)
    callback_test.go:[2](https://github.com/ebitengine/purego/actions/runs/6281280891/job/17059489504?pr=167#step:10:2)1: Build /tmp/TestCallGoFromSharedLib982910819/001/libcbtest.so
    callback_test.go:[3](https://github.com/ebitengine/purego/actions/runs/6281280891/job/17059489504?pr=167#step:10:3)0: Dlopen("/tmp/TestCallGoFromSharedLib982910819/001/libcbtest.so") failed: /tmp/TestCallGoFromSharedLib982910819/001/libcbtest.so: cannot open shared object file: No such file or directory
--- FAIL: TestNestedDlopenCall (0.06s)
    dlfcn_test.go:29: Build /tmp/TestNestedDlopenCall1035[4](https://github.com/ebitengine/purego/actions/runs/6281280891/job/17059489504?pr=167#step:10:4)48091/001/libdlnested.so
    dlfcn_test.go:38: Dlopen("/tmp/TestNestedDlopenCall103[5](https://github.com/ebitengine/purego/actions/runs/6281280891/job/17059489504?pr=167#step:10:5)44[8](https://github.com/ebitengine/purego/actions/runs/6281280891/job/17059489504?pr=167#step:10:9)0[9](https://github.com/ebitengine/purego/actions/runs/6281280891/job/17059489504?pr=167#step:10:10)1/001/libdlnested.so") failed: /tmp/TestNestedDlopenCall[10](https://github.com/ebitengine/purego/actions/runs/6281280891/job/17059489504?pr=167#step:10:11)35448091/001/libdlnested.so: cannot open shared object file: No such file or directory
FAIL

~~I don't quite understanad. Why was callback_test.go used for Linux arm64?~~ NVM, I forgot to pull the main branch

ebitengine / purego

.github/workflows: add tests for Linux arm64 #167