chore: Docker volumes with relative paths

Docker supports using relative path for bind-mounted volumes. So use
those rather than PWD. This also makes Makefile more compatible with
Windows.

Makefile

@@ -98,7 +98,7 @@ docker:
 	docker tag bat-go:$(GIT_VERSION)$(BUILD_TIME) bat-go:latest
 
 docker-reproducible:
-	docker run -v $(PWD):/workspace --network=host \
+	docker run -v .:/workspace --network=host \
 		gcr.io/kaniko-project/executor:latest \
 		--reproducible --dockerfile /workspace/Dockerfile \
 		--no-push --tarPath /workspace/bat-go-repro.tar \
@@ -190,11 +190,11 @@ format-lint:
 	make format && make lint
 
 lint: ensure-gomod-volume
-	docker run --rm -v "$$(pwd):/app" -v batgo_lint_gomod:/go/pkg --workdir /app/main golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
-	docker run --rm -v "$$(pwd):/app" -v batgo_lint_gomod:/go/pkg --workdir /app/cmd golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
-	docker run --rm -v "$$(pwd):/app" -v batgo_lint_gomod:/go/pkg --workdir /app/libs golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
-	docker run --rm -v "$$(pwd):/app" -v batgo_lint_gomod:/go/pkg --workdir /app/services golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
-	docker run --rm -v "$$(pwd):/app" -v batgo_lint_gomod:/go/pkg --workdir /app/tools golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
+	docker run --rm -v ".:/app" -v batgo_lint_gomod:/go/pkg --workdir /app/main golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
+	docker run --rm -v ".:/app" -v batgo_lint_gomod:/go/pkg --workdir /app/cmd golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
+	docker run --rm -v ".:/app" -v batgo_lint_gomod:/go/pkg --workdir /app/libs golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
+	docker run --rm -v ".:/app" -v batgo_lint_gomod:/go/pkg --workdir /app/services golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
+	docker run --rm -v ".:/app" -v batgo_lint_gomod:/go/pkg --workdir /app/tools golangci/golangci-lint:v1.49.0 golangci-lint run -v ./...
 
 download-mod:
 	cd ./cmd && go mod download && cd ..