TEST: use gcc to compile UCX in clang-tidy-rocm

The hip header file generates a warning when compiled with clang, which in itself is harmless, but because all warnings are treated as errors, the compilation fails in the UCX step. Compile UCX with gcc instead of clang (since we are not truly interested in running clang-tidy on ucx in this CI, but just on UCC)

Furthermore, force using rocm 5.6.1 instead of the newest version

.github/workflows/clang-tidy-rocm.yaml

@@ -6,7 +6,7 @@ env:
   OPEN_UCX_LINK: https://github.com/openucx/ucx
   OPEN_UCX_BRANCH: master
   CLANG_VER: 12
-  ROCM_VER: 5-4
+  ROCM_VER: 5.6.1
   LIBRARY_PATH: /tmp/ucx/install/lib
   LD_LIBRARY_PATH: /tmp/ucx/install/lib
 jobs:
@@ -23,15 +23,16 @@ jobs:
     - name: Install extra dependencies
       run: |
         curl -fsSL https://repo.radeon.com/rocm/rocm.gpg.key | sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/rocm-keyring.gpg
-        echo 'deb [arch=amd64 signed-by=/etc/apt/trusted.gpg.d/rocm-keyring.gpg]  https://repo.radeon.com/rocm/apt/debian focal main' | sudo tee /etc/apt/sources.list.d/rocm.list
+        echo 'deb [arch=amd64 signed-by=/etc/apt/trusted.gpg.d/rocm-keyring.gpg] https://repo.radeon.com/rocm/apt/5.6.1 focal main' | sudo tee /etc/apt/sources.list.d/rocm.list
+        echo -e 'Package: *\nPin: release o=repo.radeon.com\nPin-Priority: 600' | sudo tee /etc/apt/preferences.d/rocm-pin-600
         sudo apt-get update
         sudo apt-get install -y rocm-hip-sdk
-    - name: Get UCX
+    - name: Get UCX   
       run: git clone ${OPEN_UCX_LINK} -b ${OPEN_UCX_BRANCH} /tmp/ucx
     - name: Build UCX
       run: |
         cd /tmp/ucx && ./autogen.sh
-        CC=clang-${CLANG_VER} CXX=clang++-${CLANG_VER} ./contrib/configure-release --without-java --without-go --disable-numa --prefix $PWD/install --with-rocm=/opt/rocm
+        CC=gcc CXX=g++ ./contrib/configure-release --without-java --without-go --disable-numa --prefix $PWD/install --with-rocm=/opt/rocm
         make -j install
     - uses: actions/checkout@v1
     - name: Build UCC