Fix Dockerfile binary location (#337)

I know get the following

```
docker run --rm pages-server:test
12:40PM ERR A fatal error occurred error="could not create new gitea client: Get \"/api/v1/version\": unsupported protocol scheme \"\""
```

which I am not sure is OK as doing the same with v5.1 results in

```
docker run --platform linux/amd64 --rm -it codeberg.org/codeberg/pages-server:v5.1

ACME client has wrong config: you must set $ACME_ACCEPT_TERMS and $DNS_PROVIDER, unless $ACME_API is set to https://acme.mock.directory
```

The error is the same though what I get when building of 8cba7f9c8a (just before merging the multi-arch PR).
Not sure if this ERR is expected but it should be unrelated to the multiarch approach.

Reviewed-on: https://codeberg.org/Codeberg/pages-server/pulls/337
Reviewed-by: crapStone <codeberg@crapstone.dev>
Co-authored-by: pat-s <patrick.schratz@gmail.com>
Co-committed-by: pat-s <patrick.schratz@gmail.com>

Dockerfile

@@ -16,13 +16,14 @@ RUN --mount=type=cache,target=/root/.cache/go-build \
     --mount=type=cache,target=/go/pkg \
     GOOS=${TARGETOS} GOARCH=${TARGETARCH} CGO_ENABLED=1 \
     xgo -x -v --targets=${TARGETOS}/${TARGETARCH} -tags='sqlite sqlite_unlock_notify netgo' -ldflags='-s -w -extldflags "-static" -linkmode external' -out pages .
+RUN mv -vf /build/pages-* /go/src/codeberg.org/codeberg/pages/pages
 
 # Use a scratch image as the base image for the final container,
 # which will contain only the built binary and the CA certificates
 FROM scratch
 
 # Copy the built binary and the CA certificates from the build container to the final container
-COPY --from=build /go/src/codeberg.org/codeberg/pages/ /pages
+COPY --from=build /go/src/codeberg.org/codeberg/pages/pages /pages
 COPY --from=build \
     /etc/ssl/certs/ca-certificates.crt \
     /etc/ssl/certs/ca-certificates.crt