feat(tests)!: new infrastructure based on makefile

Problem: Not easy to run all checks and tests locally. Redundant CI
workflows.

Solution: Separate CI into two workflows:
 * lint: Lua files (stylua, luals), query files (valid captures,
   predicates, directives using tsqueryls), docs
   (SUPPORTED_LANGUAGES.md) -- does not need parser installation
 * tests: parsers (ABI compatibility), query files (tsqueryls on
   Linux/macOS; nvim on Windows), highlight and indent tests (separated
   for better readability) -- needs parser installation (but only once)

Switch to https://github.com/nvim-treesitter/highlight-assertions fork
with ABI 15 support.

Run all tests (on Linux and macOS) through `make` (`formatlua`,
`checklua`, `lintquery`, `formatquery`, `checkquery`, `docs`, `tests`),
which downloads and caches all necessary dependencies.

Remove `update-readme` workflow (replaced by lint job on PRs).

Makefile

@@ -0,0 +1,142 @@
+NVIM_VERSION ?= nightly
+LUALS_VERSION := 3.14.0
+
+DEPDIR ?= .test-deps
+CURL ?= curl -sL --create-dirs
+
+ifeq ($(shell uname -s),Darwin)
+    NVIM_ARCH ?= macos-arm64
+    LUALS_ARCH ?= darwin-arm64
+    STYLUA_ARCH ?= macos-aarch64
+    RUST_ARCH ?= aarch64-apple-darwin
+else
+    NVIM_ARCH ?= linux-x86_64
+    LUALS_ARCH ?= linux-x64
+    STYLUA_ARCH ?= linux-x86_64
+    RUST_ARCH ?= x86_64-unknown-linux-gnu
+endif
+
+.DEFAULT_GOAL := all
+
+# download test dependencies
+
+NVIM := $(DEPDIR)/nvim-$(NVIM_ARCH)
+NVIM_TARBALL := $(NVIM).tar.gz
+NVIM_URL := https://github.com/neovim/neovim/releases/download/$(NVIM_VERSION)/$(notdir $(NVIM_TARBALL))
+NVIM_BIN := $(NVIM)/nvim-$(NVIM_ARCH)/bin/nvim
+NVIM_RUNTIME=$(NVIM)/nvim-$(NVIM_ARCH)/share/nvim/runtime
+
+.PHONY: nvim
+nvim: $(NVIM)
+
+$(NVIM):
+	$(CURL) $(NVIM_URL) -o $(NVIM_TARBALL)
+	mkdir $@
+	tar -xf $(NVIM_TARBALL) -C $@
+	rm -rf $(NVIM_TARBALL)
+
+LUALS := $(DEPDIR)/lua-language-server-$(LUALS_VERSION)-$(LUALS_ARCH)
+LUALS_TARBALL := $(LUALS).tar.gz
+LUALS_URL := https://github.com/LuaLS/lua-language-server/releases/download/$(LUALS_VERSION)/$(notdir $(LUALS_TARBALL))
+
+.PHONY: luals
+luals: $(LUALS)
+
+$(LUALS):
+	$(CURL) $(LUALS_URL) -o $(LUALS_TARBALL)
+	mkdir $@
+	tar -xf $(LUALS_TARBALL) -C $@
+	rm -rf $(LUALS_TARBALL)
+
+STYLUA := $(DEPDIR)/stylua-$(STYLUA_ARCH)
+STYLUA_TARBALL := $(STYLUA).zip
+STYLUA_URL := https://github.com/JohnnyMorganz/StyLua/releases/latest/download/$(notdir $(STYLUA_TARBALL))
+
+.PHONY: stylua
+stylua: $(STYLUA)
+
+$(STYLUA):
+	$(CURL) $(STYLUA_URL) -o $(STYLUA_TARBALL)
+	unzip $(STYLUA_TARBALL) -d $(STYLUA)
+	rm -rf $(STYLUA_TARBALL)
+
+TSQUERYLS := $(DEPDIR)/ts_query_ls-$(RUST_ARCH)
+TSQUERYLS_TARBALL := $(TSQUERYLS).tar.gz
+TSQUERYLS_URL := https://github.com/ribru17/ts_query_ls/releases/latest/download/$(notdir $(TSQUERYLS_TARBALL))
+
+.PHONY: tsqueryls
+tsqueryls: $(TSQUERYLS)
+
+$(TSQUERYLS):
+	$(CURL) $(TSQUERYLS_URL) -o $(TSQUERYLS_TARBALL)
+	mkdir $@
+	tar -xf $(TSQUERYLS_TARBALL) -C $@
+	rm -rf $(TSQUERYLS_TARBALL)
+
+HLASSERT := $(DEPDIR)/highlight-assertions-$(RUST_ARCH)
+HLASSERT_TARBALL := $(HLASSERT).tar.gz
+HLASSERT_URL := https://github.com/nvim-treesitter/highlight-assertions/releases/latest/download/$(notdir $(HLASSERT_TARBALL))
+
+.PHONY: hlassert
+hlassert: $(HLASSERT)
+
+$(HLASSERT):
+	$(CURL) $(HLASSERT_URL) -o $(HLASSERT_TARBALL)
+	mkdir $@
+	tar -xf $(HLASSERT_TARBALL) -C $@
+	rm -rf $(HLASSERT_TARBALL)
+
+PLENARY := $(DEPDIR)/plenary.nvim
+
+.PHONY: plenary
+plenary: $(PLENARY)
+
+$(PLENARY):
+	git clone --filter=blob:none https://github.com/nvim-lua/plenary.nvim $(PLENARY)
+
+# actual test targets
+
+.PHONY: lua
+lua: formatlua checklua
+
+.PHONY: formatlua
+formatlua: $(STYLUA)
+	$(STYLUA)/stylua .
+
+.PHONY: checklua
+checklua: $(LUALS) $(NVIM)
+	VIMRUNTIME=$(NVIM_RUNTIME) $(LUALS)/bin/lua-language-server \
+		--configpath=../.luarc.json \
+		--check=./
+
+.PHONY: query
+query: formatquery lintquery checkquery
+
+.PHONY: lintquery
+lintquery: $(TSQUERYLS)
+	$(TSQUERYLS)/ts_query_ls lint runtime/queries
+
+.PHONY: formatquery
+formatquery: $(TSQUERYLS)
+	$(TSQUERYLS)/ts_query_ls format runtime/queries
+
+.PHONY: checkquery
+checkquery: $(TSQUERYLS)
+	$(TSQUERYLS)/ts_query_ls check runtime/queries
+
+.PHONY: docs
+docs: $(NVIM)
+	$(NVIM_BIN) -l scripts/update-readme.lua
+
+.PHONY: tests
+tests: $(NVIM) $(HLASSERT) $(PLENARY)
+	HLASSERT=$(HLASSERT)/highlight-assertions PLENARY=$(PLENARY) \
+		$(NVIM_BIN) --headless --clean -u scripts/minimal_init.lua \
+		-c "PlenaryBustedDirectory tests/$(TESTS) { minimal_init = './scripts/minimal_init.lua' }"
+
+.PHONY: all
+all: lua query docs tests
+
+.PHONY: clean
+clean:
+	rm -rf $(DEPDIR)