fix: Disable fail-fast for build-installer jobs

Allow all platform builds to complete independently so that a failure
on one platform doesn't cancel the others.

Author: chrisburr

.github/workflows/build-and-test.yml

@@ -19,6 +19,7 @@ jobs:
     if: github.repository == 'DIRACGrid/DIRACOS2'
     runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: false
       matrix:
         include:
           - target_arch: linux-64