[Github] Remove call to llvm-project-tests from libclang tests

This allows for removing llvm-project-tests.yml. This significantly
reduces the complexity of this workflow (including the complexity of
llvm-project-tests.yml) at the cost of a little bit of duplication with
the other workflows that were also using llvm-project-tests.yml.

Reviewers: tstellar, DeinAlptraum

Reviewed By: DeinAlptraum

Pull Request: #153876

Author: boomanaiden154

.github/workflows/libclang-python-tests.yml

@@ -4,7 +4,6 @@ permissions:
   contents: read
 
 on:
-  workflow_dispatch:
   push:
     branches:
       - 'main'
@@ -13,29 +12,46 @@ on:
       - 'clang/tools/libclang/**'
       - 'clang/CMakeList.txt'
       - '.github/workflows/libclang-python-tests.yml'
-      - '.github/workflows/llvm-project-tests.yml'
   pull_request:
     paths:
       - 'clang/bindings/python/**'
       - 'clang/tools/libclang/**'
       - 'clang/CMakeList.txt'
       - '.github/workflows/libclang-python-tests.yml'
-      - '.github/workflows/llvm-project-tests.yml'
 
 jobs:
   check-clang-python:
     # Build libclang and then run the libclang Python binding's unit tests.
+    # There is an issue running on "windows-2019".
+    # See https://github.com/llvm/llvm-project/issues/76601#issuecomment-1873049082.
     name: Build and run Python unit tests
     if: github.repository == 'llvm/llvm-project'
+    runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
       matrix:
         python-version: ["3.8", "3.13"]
-    uses: ./.github/workflows/llvm-project-tests.yml
-    with:
-      build_target: check-clang-python
-      projects: clang
-      # There is an issue running on "windows-2019".
-      # See https://github.com/llvm/llvm-project/issues/76601#issuecomment-1873049082.
-      os_list: '["ubuntu-24.04"]'
-      python_version: ${{ matrix.python-version }}
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+      - name: Setup Python
+        uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Setup ccache
+        uses: hendrikmuhs/ccache-action@a1209f81afb8c005c13b4296c32e363431bffea5 # v1.2.17
+        with:
+          max-size: 2G
+          key: spirv-ubuntu-24.04
+          variant: sccache
+      - name: Build and Test
+        run: |
+          mkdir build
+          cmake -GNinja \
+            -S llvm \
+            -B build \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DLLVM_ENABLE_ASSERTIONS=ON \
+            -DCMAKE_C_COMPILER_LAUNCHER=sccache \
+            -DCMAKE_CXX_COMPILER_LAUNCHER=sccache \
+            -DLLVM_ENABLE_PROJECTS=clang
+          ninja -C build check-clang-python