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).

.github/workflows/test-core.yml

@@ -35,7 +35,7 @@ jobs:
         name: Generate and compile parsers
         run: $NVIM -l ./scripts/install-parsers.lua --generate --max-jobs=2
 
-      - if: inputs.type == 'queries'
+      - if: inputs.type == 'build'
         name: Setup Parsers Cache
         id: parsers-cache
         uses: actions/cache@v4
@@ -47,9 +47,25 @@ jobs:
             './lua/nvim-treesitter/install.lua',
             './lua/nvim-treesitter/parsers.lua') }}
 
-      - if: inputs.type == 'queries'
+      - if: inputs.type == 'build'
         name: Compile parsers
         run: $NVIM -l ./scripts/install-parsers.lua
 
-      - name: Check query files
+      - name: Check parsers
+        run: $NVIM -l ./scripts/check-parsers.lua
+
+      - name: Check queries (nvim)
+        if: ${{ matrix.os == 'windows-latest' }}
         run: $NVIM -l ./scripts/check-queries.lua
+
+      - name: Check queries (tsqueryls)
+        if: ${{ matrix.os != 'windows-latest' }}
+        run: make checkquery
+
+      - name: Run highlight tests
+        if: ${{ matrix.os != 'windows-latest' }}
+        run: make tests TESTS=query NVIM_BIN=$NVIM
+
+      - name: Run indents tests
+        if: ${{ matrix.os != 'windows-latest' }}
+        run: make tests TESTS=indent NVIM_BIN=$NVIM