ci: blackduck: Clean-up Blackduck scan

Currently, Black Duck is scanning many parts of the codebase that are not relevant to the final firmware.
This leads to longer scan times, unnecessary findings, and additional overhead when reviewing the results.

This ticket addresses the removal of the following directories from the scan.

    * build_dir/host/
    * build_dir/hostpkg/
    * staging_dir/host/
    * staging_dir/hostpkg/
    * DB
    * mruby
    * mbedtls
    * gnutls krb5
    * linux-pam

Closes: PCF-2255, PCF-2254
Signed-off-by: Mouna Aloui <mouna.aloui@softathome.com>

.gitlab/blackduck.yml

@@ -17,6 +17,16 @@
     - sudo apt install openjdk-17-jdk -y
     - curl -s --output detect.sh https://detect.blackduck.com/detect10.sh
     - sudo chmod +x detect.sh
+    - |
+      rm -rf \
+        build_dir/target-*/prplos-sdk-* \
+        build_dir/target-*/prplos-imagebuilder-* \
+        build_dir/target-*/krb5-* \
+        build_dir/target-*/gnutls-* \
+        build_dir/target-*/mbedtls-* \
+        build_dir/target-*/Linux-PAM-* \
+        build_dir/target-*/db-* \
+        build_dir/target-*/lrzsz-*
     - |
       for dir in $(ls -d build_dir/target-*/*); do
         ./detect.sh \