chore: use opam to simplify makefile (#361)

Let's install check-jsonschema via depexts!
See semgrep/semgrep-proprietary#3273 for more
context

- [X] I ran `make setup && make` to update the generated code after
editing a `.atd` file (TODO: have a CI check)
- [X] I made sure we're still backward compatible with old versions of
the CLI.
For example, the Semgrep backend need to still be able to *consume* data
	  generated by Semgrep 1.50.0.
See
https://atd.readthedocs.io/en/latest/atdgen-tutorial.html#smooth-protocol-upgrades
	  Note that the types related to the semgrep-core JSON output or the
	  semgrep-core RPC do not need to be backward compatible!

Author: ajbt200128

Makefile

@@ -72,24 +72,16 @@ clean:
 # This takes a while but ensures we use the correct versions of the atd tools.
 .PHONY: setup
 setup:
+	opam update -y
+	opam install -y --deps-only ./semgrep-interfaces.opam
 	# Please install check-jsonschema (Python tool) if this fails:
 	check-jsonschema --version
-	opam update -y
-	opam install -y --deps-only ./dev.opam
-
-.PHONY: setup-ALPINE
-setup-ALPINE: setup-PYTHON
-
-.PHONY: setup-MACOS
-setup-MACOS:
-	brew install check-jsonschema
 
 .PHONY: setup-PYTHON
 setup-PYTHON:
 	pip install check-jsonschema
 
 # The tests require semgrep-core, among other things.
-#
 .PHONY: test
 test:
 	$(MAKE) -C tests

dev.opam

@@ -0,0 +1,31 @@
+# This is meant to be installed with 'opam install --deps-only . '
+#
+opam-version: "2.0"
+maintainer: "semgrep"
+authors: "r2c"
+homepage: "n/a"
+bug-reports: "n/a"
+synopsis: "Interfaces for Semgrep"
+dev-repo: "git+https://github.com/semgrep/semgrep-interfaces.git"
+license: "LGPL-2.1-only"
+
+build: []
+install: []
+          
+depends: [
+  "atd" {>= "2.6.0"}
+  "atdpy" {>= "2.12.0"}
+  "atdts" {>= "2.13.0"}
+  "atdgen" {>= "2.10.0"}
+]
+
+#TODO: we don't build on ubuntu or debian ever, and they are not packages there,
+# so let's just ignore it for now
+#["check-jsonschema"] {os-family = "debian"}
+#["check-jsonschema"] {os-family = "ubuntu"}
+depexts: [
+   ["check-jsonschema"] {os-distribution = "alpine"}
+   ["check-jsonschema"] {os = "macos" & os-distribution = "homebrew"}
+   ["check-jsonschema"] {os = "macos" & os-distribution = "macports"}
+   ["check-jsonschema"] {os = "win32" & os-distribution = "macports"}
+]