Fix the macos cross build within the OCP builder image

Fix the cross-compilation issue without disabling CGO. The problem was
that the macOS SDK 10.15 in the builder image doesn't have the
SecTrustCopyCertificateChain symbol that Go 1.25's crypto/x509 package
requires (this API was introduced in macOS 12.0).

Use the -Wl,-undefined,dynamic_lookup linker flag for macOS
cross-compilation. This tells the linker to allow undefined symbols
that will be resolved at runtime.

The alternative would be to disable CGO.

Signed-off-by: Todd Short <[email protected]>
Assisted by: Claude Code

Author: tmshort

Makefile

@@ -101,7 +101,7 @@ $(COLLECT_PROFILES_CMD): FORCE
 cross: version_flags=-X '$(REGISTRY_PKG)/cmd/opm/version.gitCommit=$(GIT_COMMIT)' -X '$(REGISTRY_PKG)/cmd/opm/version.opmVersion=$(OPM_VERSION)' -X '$(REGISTRY_PKG)/cmd/opm/version.buildDate=$(BUILD_DATE)'
 cross:
 ifeq ($(shell go env GOARCH),amd64)
-	GOOS=darwin CC=o64-clang CXX=o64-clang++ CGO_ENABLED=1 go build $(GO_BUILD_OPTS) $(GO_BUILD_TAGS) -o "bin/darwin-amd64-opm" --ldflags "-extld=o64-clang $(version_flags)" $(REGISTRY_PKG)/cmd/opm
+	GOOS=darwin CC=o64-clang CXX=o64-clang++ CGO_ENABLED=1 CGO_LDFLAGS='-Wl,-undefined,dynamic_lookup' go build $(GO_BUILD_OPTS) $(GO_BUILD_TAGS) -o "bin/darwin-amd64-opm" --ldflags "-extld=o64-clang -extldflags=-Wl,-undefined,dynamic_lookup $(version_flags)" $(REGISTRY_PKG)/cmd/opm
 	GOOS=windows CC=x86_64-w64-mingw32-gcc CXX=x86_64-w64-mingw32-g++ CGO_ENABLED=1 go build $(GO_BUILD_OPTS) $(GO_BUILD_TAGS) -o "bin/windows-amd64-opm" --ldflags "-extld=x86_64-w64-mingw32-gcc $(version_flags)" -buildmode=exe $(REGISTRY_PKG)/cmd/opm
 endif