Merge bitcoin/bitcoin#29094: ci: Better tidy errors

fae70ba00d ci: Better tidy errors (MarcoFalke)

Pull request description:

  Currently tidy errors are not nice, because the user may have to scroll up to see them in a large block of text. See for example (before) https://github.com/bitcoin/bitcoin/runs/19670551485

  Fix that by `tee`ing the output to a file and summarizing the errors in the end again. See for example (after): https://github.com/bitcoin/bitcoin/runs/22647850662

ACKs for top commit:
  hebasto:
    ACK fae70ba00d, logs with errors look cleaner.
  TheCharlatan:
    ACK fae70ba00d

Tree-SHA512: dcaea557fed40089409d16ce2cbaa8a9cfbf047f601d5daadfee0823b0eed7badc12d803addc0b7b6bb3f1eaf5c787fccb2488475d32c4efd80835f386f761dd

ci/test/03_test_script.sh

@@ -182,7 +182,11 @@ if [ "${RUN_TIDY}" = "true" ]; then
 
   set -eo pipefail
   cd "${BASE_BUILD_DIR}/bitcoin-$HOST/src/"
-  ( run-clang-tidy-"${TIDY_LLVM_V}" -quiet -load="/tidy-build/libbitcoin-tidy.so" "${MAKEJOBS}" ) | grep -C5 "error"
+  if ! ( run-clang-tidy-"${TIDY_LLVM_V}" -quiet -load="/tidy-build/libbitcoin-tidy.so" "${MAKEJOBS}" | tee tmp.tidy-out.txt ); then
+    grep -C5 "error: " tmp.tidy-out.txt
+    echo "^^^ ⚠️ Failure generated from clang-tidy"
+    false
+  fi
   # Filter out files by regex here, because regex may not be
   # accepted in src/.bear-tidy-config
   # Filter out: