feat: install most dependencies in cacheable layer, before adding main

Instead of requiring the whole stack to be reinstalled whenever a specific version (e.g. main) causes a cache fail, this aims to have stable default version with a second-stage installation of the potentially-modified versions of eicrecon and juggler. This should allow all builds to cache the first installation in virtually all cases, leading to faster builds.

.gitlab-ci.yml

@@ -63,8 +63,8 @@ workflow:
     - if: '$CI_PIPELINE_SOURCE == "merge_request_event"'
     - if: '$CI_PIPELINE_SOURCE == "web"'
     - if: '$CI_COMMIT_BRANCH == "master"'
-    - if: '$CI_COMMIT_BRANCH =~ /^v[0-9]+\.[0-9]+-stable/'          ## main stable branch: vX.Y-stable
-    - if: '$CI_COMMIT_BRANCH =~ /^v[0-9]+\.[0-9]+-[a-z]+-stable/'   ## special stable branch: vX.Y-acadia-stable (etc)
+    - if: '$CI_COMMIT_BRANCH =~ /^v[0-9]+\.[0-9]+-\(alpha\|beta\|stable\)/'          ## main stable branch: vX.Y-stable
+    - if: '$CI_COMMIT_BRANCH =~ /^v[0-9]+\.[0-9]+-[a-z]+-\(alpha\|beta\|stable\)/'   ## special stable branch: vX.Y-acadia-stable (etc)
     - if: '$CI_COMMIT_TAG =~ /^v[0-9]+\.[0-9]+\.[0-9]+/'            ## commit tags start with vX.Y.Z with optional suffix
 
 ## plan:
@@ -107,10 +107,10 @@ version:
       elif [[ "$CI_COMMIT_TAG" =~ ^v[0-9.]+\.[0-9]+\.[0-9]+ ]]; then
         VERSION="${CI_COMMIT_TAG:1}"
         EXPORT_TAG="${VERSION}"
-      elif [[ "$CI_COMMIT_BRANCH" =~ ^v[0-9.]+\.[0-9]+-stable ]]; then
+      elif [[ "$CI_COMMIT_BRANCH" =~ ^v[0-9.]+\.[0-9]+-\(alpha\|beta\|stable\) ]]; then
         VERSION="${CI_COMMIT_BRANCH:1}"
         EXPORT_TAG="${VERSION}"
-      elif [[ "$CI_COMMIT_BRANCH" =~ ^v[0-9.]+\.[0-9]+-[a-z]+-stable ]]; then
+      elif [[ "$CI_COMMIT_BRANCH" =~ ^v[0-9.]+\.[0-9]+-[a-z]+-\(alpha\|beta\|stable\) ]]; then
         VERSION="${CI_COMMIT_BRANCH:1}"
         EXPORT_TAG="${VERSION}"
       elif [[ "$CI_COMMIT_BRANCH" =~ ^master$ ]]; then