MM-46275/MM-46979 Production MPA for web app (#21401)

* MM-46275 Unify various targets for building web app

* MM-46275/MM-46979 Add logic to package boards product static files in CI

* Add error meessage when Boards files can't be found during packaging

* Remove a couple unneeded lines from release.mk

* Decrease size of machine used for setup-focalboard-product

* Revert "Add error meessage when Boards files can't be found during packaging"

This reverts commit f4f46ade0ac4c1ec5525d9b2eae959e13b9aec42.

* Revert "Revert "Add error meessage when Boards files can't be found during packaging""

This reverts commit a0e6420b19c5af0b5ff4706b6abaf8e56f8b3495.

* Fix unrelated email templates

* Skip flaky test

build/release.mk

@@ -190,6 +190,17 @@ else
 	done
 endif
 
+	@# Products
+
+	@if [ -d $(BUILD_BOARDS_DIR) ] ; then \
+		echo "Copying web app files for Boards product"; \
+		mkdir -p $(DIST_PATH_GENERIC)/client/products/boards; \
+		cp -R $(BUILD_BOARDS_DIR)/mattermost-plugin/webapp/dist/* $(DIST_PATH_GENERIC)/client/products/boards/; \
+	else \
+		echo "Unable to find files for Boards product. Please ensure that the Focalboard repository is checked out alongside the server and run 'make build-product' in it."; \
+		exit 1; \
+	fi
+
 package-osx-amd64: package-prep
 	DIST_PATH_GENERIC=$(DIST_PATH_OSX_AMD64) CURRENT_PACKAGE_ARCH=darwin_amd64 PLUGIN_ARCH=osx-amd64 MMCTL_PLATFORM="Darwin-x86_64" MM_BIN_NAME=mattermost $(MAKE) package-general
 	@# Package