fix(CI): Provide CLANG_PATH to work around multitude of installed clangs

.github/workflows/main.yml

@@ -20,6 +20,13 @@ jobs:
       SCCACHE_GHA_ENABLED: "true"
       RUSTC_WRAPPER: "sccache"
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      # clang-sys and thus bindgen is sensitive to multiple installed versions
+      # around, see eg. https://github.com/rust-lang/rust-bindgen/issues/2682
+      #
+      # CLANG_PATH should be set to the most recent clang installed, no matter
+      # what /usr/bin/clang is, for some parts of the code will go for the
+      # newest standard library.
+      CLANG_PATH: /usr/bin/clang-15
 
     strategy:
       fail-fast: false