Merge #5938: ci: adjust amount of parallel jobs from 4 to variable

86dd0eabb4 chore: increase amount of build jobs from 4 to 8 for depends (Konstantin Akimov)

Pull request description:

  ## What was done?
  Bump CI yaml to use 8 threads for build depends

  ## How Has This Been Tested?
  Builds logs says:
  ```
  $ make -j$(nproc) -C depends HOST=$HOST $DEP_OPTS
  make: Entering directory '/builds/dashpay/dash/depends'
  ```
  https://gitlab.com/dashpay/dash/-/jobs/6409522172

  ## Breaking Changes
  N/A

  ## Checklist:
  - [x] I have performed a self-review of my own code
  - [ ] I have commented my code, particularly in hard-to-understand areas
  - [ ] I have added or updated relevant unit/integration/functional/e2e tests
  - [ ] I have made corresponding changes to the documentation
  - [x] I have assigned this pull request to a milestone

ACKs for top commit:
  PastaPastaPasta:
    utACK 86dd0eabb4

Tree-SHA512: dfdcae5473a5315d3fc64721f432d671a14cab9811305334f948a73ddc13e5f3e58be433988030ef6019cddd3f383c87722eaed40d8b3ab570e5c224c20191e0

.gitlab-ci.yml

@@ -44,7 +44,6 @@ builder-image:
     SDK_URL: https://bitcoincore.org/depends-sources/sdks
     XCODE_VERSION: "12.2"
     XCODE_BUILD_ID: 12B45b
-    MAKEJOBS: -j4
   before_script:
     - echo HOST=$HOST
     - |
@@ -63,7 +62,7 @@ builder-image:
         fi
       fi
   script:
-    - make $MAKEJOBS -C depends HOST=$HOST $DEP_OPTS
+    - make -j$(nproc) -C depends HOST=$HOST $DEP_OPTS
   cache:
     # Let all branches share the same cache, which is ok because the depends subsystem is able to handle this properly (it works with hashes of all scripts)
     key: