Permit custom Make targets (#1094)

The standard workflows are great, but sometimes build-time complexity is
a necessary evil for temporary or experimental features. One concrete
use case is simplifying computing the minimal schema in AWS:

     pulumi/pulumi-aws#4587

This small change permits providers to define *.mk files to add some
provider-specific extensions to Make.

provider-ci/internal/pkg/templates/bridged-provider/Makefile

@@ -282,3 +282,6 @@ provider_dist-darwin-arm64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-darwin-arm64.tar
 provider_dist-windows-amd64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-windows-amd64.tar.gz
 provider_dist: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64
 .PHONY: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64 provider_dist
+
+# Permit providers to extend the Makefile with provider-specific Make includes.
+include $(wildcard .mk/*.mk)

provider-ci/test-providers/acme/Makefile

@@ -242,3 +242,6 @@ provider_dist-darwin-arm64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-darwin-arm64.tar
 provider_dist-windows-amd64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-windows-amd64.tar.gz
 provider_dist: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64
 .PHONY: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64 provider_dist
+
+# Permit providers to extend the Makefile with provider-specific Make includes.
+include $(wildcard .mk/*.mk)

provider-ci/test-providers/aws/Makefile

@@ -257,3 +257,6 @@ provider_dist-darwin-arm64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-darwin-arm64.tar
 provider_dist-windows-amd64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-windows-amd64.tar.gz
 provider_dist: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64
 .PHONY: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64 provider_dist
+
+# Permit providers to extend the Makefile with provider-specific Make includes.
+include $(wildcard .mk/*.mk)

provider-ci/test-providers/cloudflare/Makefile

@@ -250,3 +250,6 @@ provider_dist-darwin-arm64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-darwin-arm64.tar
 provider_dist-windows-amd64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-windows-amd64.tar.gz
 provider_dist: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64
 .PHONY: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64 provider_dist
+
+# Permit providers to extend the Makefile with provider-specific Make includes.
+include $(wildcard .mk/*.mk)

provider-ci/test-providers/docker/Makefile

@@ -251,3 +251,6 @@ provider_dist-darwin-arm64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-darwin-arm64.tar
 provider_dist-windows-amd64: bin/$(PROVIDER)-v$(VERSION_GENERIC)-windows-amd64.tar.gz
 provider_dist: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64
 .PHONY: provider_dist-linux-amd64 provider_dist-linux-arm64 provider_dist-darwin-amd64 provider_dist-darwin-arm64 provider_dist-windows-amd64 provider_dist
+
+# Permit providers to extend the Makefile with provider-specific Make includes.
+include $(wildcard .mk/*.mk)