Closed issue by Shanduur on void-packages repository

https://github.com/void-linux/void-packages/issues/39315

Description:
Adding the new parameter into the template (`go_cgo_enabled`) that can be translated directly to the `CGO_ENABLED`. This could be helpful when building packages than can be built with both go and cgo. I have encountered this issue when preparing the package for [promtail (loki client/exporter)](https://grafana.com/docs/loki/latest/clients/promtail/). When using `CGO_ENABLED=1`, it requires systemd specific header files:

```gcc
# github.com/coreos/go-systemd/sdjournal
vendor/github.com/coreos/go-systemd/sdjournal/journal.go:27:11: fatal error: systemd/sd-journal.h: No such file or directory
   27 | // #include <systemd/sd-journal.h>
      |           ^~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
```

Setting `CGO_ENABLED=0` is a way to skip cgo compilation.

Proposal:
```diff
diff --git a/common/build-style/go.sh b/common/build-style/go.sh
index 9093527860..83006a5adf 100644
--- a/common/build-style/go.sh
+++ b/common/build-style/go.sh
@@ -22,6 +22,10 @@ do_configure() {
 }

 do_build() {
+       if [[ -z ${go_cgo_enabled} ]]; then
+               go_cgo_enabled=1
+       fi
+
        # remove -s and -w from go_ldflags, we should let xbps-src strip binaries itself
        for wd in $go_ldflags; do
                if [ "$wd" == "-s" ] || [ "$wd" == "-w" ]; then
@@ -40,7 +44,7 @@ do_build() {
                        # default behavior.
                        go_mod_mode=
                fi
-               go install -p "$XBPS_MAKEJOBS" -mod="${go_mod_mode}" -x -tags "${go_build_tags}" -ldflags "${go_ldflags}" ${go_package}
+               CGO_ENABLED=${go_cgo_enabled} go install -p "$XBPS_MAKEJOBS" -mod="${go_mod_mode}" -x -tags "${go_build_tags}" -ldflags "${go_ldflags}" ${go_package}
        else
                # Otherwise, build using GOPATH
                go get -p "$XBPS_MAKEJOBS" -x -tags "${go_build_tags}" -ldflags "${go_ldflags}" ${go_package}
```