fix shellcheck errors in .ci/install-clang-devel.sh

- Used double quotes around entire word as suggested 
-  #6498

.ci/install-clang-devel.sh

@@ -32,22 +32,22 @@ add-apt-repository -y "deb-src http://apt.llvm.org/unstable/ llvm-toolchain-${CL
 apt-get update -y
 
 apt-get install -y --no-install-recommends \
-    clang-"${CLANG_VERSION}" \
-    clangd-"${CLANG_VERSION}" \
-    clang-format-"${CLANG_VERSION}" \
-    clang-tidy-"${CLANG_VERSION}" \
-    clang-tools-"${CLANG_VERSION}" \
-    lldb-"${CLANG_VERSION}" \
-    lld-"${CLANG_VERSION}" \
-    llvm-"${CLANG_VERSION}"-dev \
-    llvm-"${CLANG_VERSION}"-tools \
-    libomp-"${CLANG_VERSION}"-dev \
-    libc++-"${CLANG_VERSION}"-dev \
-    libc++abi-"${CLANG_VERSION}"-dev \
-    libclang-common-"${CLANG_VERSION}"-dev \
-    libclang-"${CLANG_VERSION}"-dev \
-    libclang-cpp"${CLANG_VERSION}"-dev \
-    libunwind-"${CLANG_VERSION}"-dev
+    "clang-${CLANG_VERSION}" \
+    "clangd-${CLANG_VERSION}" \
+    "clang-format-${CLANG_VERSION}" \
+    "clang-tidy-${CLANG_VERSION}" \
+    "clang-tools-${CLANG_VERSION}" \
+    "lldb-${CLANG_VERSION}" \
+    "lld-${CLANG_VERSION}" \
+    "llvm-${CLANG_VERSION}"-dev \
+    "llvm-${CLANG_VERSION}"-tools \
+    "libomp-${CLANG_VERSION}"-dev \
+    "libc++-${CLANG_VERSION}"-dev \
+    "libc++abi-${CLANG_VERSION}"-dev \
+    "libclang-common-${CLANG_VERSION}"-dev \
+    "libclang-${CLANG_VERSION}"-dev \
+    "libclang-cpp${CLANG_VERSION}"-dev \
+    "libunwind-${CLANG_VERSION}"-dev
 
 # overwriting the stuff in /usr/bin is simpler and more reliable than
 # updating PATH, LD_LIBRARY_PATH, etc.