sagemathgh-36767: Reduce execution time of conda workflow
    
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Reduces the executation time of the conda workflow to 2h, so that it is
quicker than the "Build & Test" workflow and devs no longer have to wait
5h until their PR turns green. It also reduces the likelihood that the
conda workflows queue up as now all available macos runners are utilized
immediately.
From
sagemath#36694 (comment).

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URL: sagemath#36767
Reported by: Tobias Diez
Reviewer(s):

Author: Release Manager

.github/workflows/ci-conda.yml

@@ -21,8 +21,6 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     strategy:
-      fail-fast: ${{ github.event_name == 'pull_request' }}
-      max-parallel: ${{ github.event_name == 'pull_request' && 2 || 6 }}
       matrix:
         os: [ubuntu-latest, macos-latest]
         python: ['3.9', '3.10', '3.11']