fix: skip heavy recursion tests in debug builds (#22446)

## Summary
Instead of bumping timeouts for slow tests in debug mode, skip them
entirely.

`HonkRecursionConstraintTest` and `ChonkRecursionConstraintTest` take
400-600s in debug builds, hitting the 600s default timeout. These are
heavy recursion constraint tests that build full recursive circuits —
the same code paths are already exercised (with debug assertions) by
faster tests in the suite.

This replaces the timeout-bump approach from PR #22347 with Adam's
suggestion to be selective about what runs in debug mode.

Supersedes #22427

ClaudeBox log: https://claudebox.work/s/c3fd56d2f55c879c?run=2

Author: AztecBot

barretenberg/cpp/bootstrap.sh

@@ -245,16 +245,17 @@ function test_cmds_native {
       awk '/^[a-zA-Z]/ {suite=$1} /^[ ]/ {print suite$1}' | \
       grep -v 'DISABLED_' | \
       while read -r test; do
+        # Skip heavy recursion tests in debug builds — they take 400-600s and the same
+        # code paths are already exercised (with assertions) by faster tests in the suite.
+        if [[ "$native_preset" == *debug* ]] && [[ "$test" =~ ^(HonkRecursionConstraintTest|ChonkRecursionConstraintTest) ]]; then
+          continue
+        fi
         local prefix=$hash
         # A little extra resource for these tests.
         # IPARecursiveTests fails with 2 threads.
         if [[ "$test" =~ ^(AcirAvmRecursionConstraint|ChonkKernelCapacity|AvmRecursiveTests|IPARecursiveTests|HonkRecursionConstraintTest|ChonkRecursionConstraintTest) ]]; then
           prefix="$prefix:CPUS=4:MEM=8g"
         fi
-        # These tests routinely take 400-600s in debug builds; bump from the 600s default.
-        if [[ "$test" =~ ^(HonkRecursionConstraintTest|ChonkRecursionConstraintTest) ]]; then
-          prefix="$prefix:TIMEOUT=900s"
-        fi
         echo -e "$prefix barretenberg/cpp/scripts/run_test.sh $bin_name $test"
       done || (echo "Failed to list tests in $bin" && exit 1)
   done