test: disable mc client tests from test matrix

The dl.min.io download site has been having stability issues
possibly related to github action runners getting rate limited.
Disable these for now until we can find a better place to host
this client.

README.md

@@ -90,7 +90,6 @@ Our multi-layered testing strategy includes:
 - **System Tests** - Protocol-level validation using industry-standard S3 clients:
   - AWS CLI - Official AWS command-line tools
   - s3cmd - Popular S3 client
-  - MinIO mc - Modern S3-compatible client
   - Direct REST API testing with curl for request/response validation
 - **Security Testing** - Both HTTP and HTTPS configurations tested. Vulnerability scanning with govulncheck. And regular dependency updates with dependabot.
 - **Compatibility Testing** - Multiple backends, versioning scenarios, static bucket modes, and various authentication methods.

tests/generate_matrix.sh

@@ -20,15 +20,36 @@ source ./tests/drivers/params.sh
 
 set -euo pipefail
 
+# Tests to exclude from the matrix (matched against file basename without extension)
+skip_list=(
+  "mc"
+  "mc_file_count"
+)
+
 files=()
 iam_types=()
 regions=()
 idx=0
 
+is_skipped() {
+  local basename="${1##*/}"
+  local name="${basename%.sh}"
+  name="${name#test_}"
+  for skip in "${skip_list[@]}"; do
+    if [[ "$name" == "$skip" ]]; then
+      return 0
+    fi
+  done
+  return 1
+}
+
 check_for_and_load_test_file_and_params() {
   if ! check_param_count_v2 "file name" 1 $#; then
     exit 1
   fi
+  if is_skipped "$1"; then
+    return 0
+  fi
   if grep -q '@test' "$1"; then
     if [ $(( idx % 8 )) -eq 0 ]; then
       iam="s3"