Update julia

Changes:

- https://github.com/docker-library/julia/commit/92c1731: Merge pull request https://github.com/docker-library/julia/pull/47 from lungben/master
- https://github.com/docker-library/julia/commit/4c89f47: Exclude Alpine variants in GitHub Actions i386 test builds
- https://github.com/docker-library/julia/commit/fb8e276: Add Alpine template and resync with how Debian images are structured
- https://github.com/docker-library/julia/commit/9297767: Dockerfile for Alpine-based Julia 1.5 added

library/julia

@@ -1,4 +1,4 @@
-# this file is generated via https://github.com/docker-library/julia/blob/23ad05df7adeead8a8962d8d645fa3f5004f323b/generate-stackbrew-library.sh
+# this file is generated via https://github.com/docker-library/julia/blob/fb8e27612702b2dc93f109947a4df0f99477f3b0/generate-stackbrew-library.sh
 
 Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
@@ -10,6 +10,11 @@ Architectures: amd64, arm64v8, i386
 GitCommit: 6a716f3d1f28aaafce298c33e27a053443eec6fb
 Directory: 1.5-rc/buster
 
+Tags: 1.5.0-rc1-alpine3.12, 1.5.0-alpine3.12, 1.5-alpine3.12, 1.5-rc-alpine3.12, rc-alpine3.12, 1.5.0-rc1-alpine, 1.5.0-alpine, 1.5-alpine, 1.5-rc-alpine, rc-alpine
+Architectures: amd64
+GitCommit: fb8e27612702b2dc93f109947a4df0f99477f3b0
+Directory: 1.5-rc/alpine3.12
+
 Tags: 1.5.0-rc1-windowsservercore-ltsc2016, 1.5.0-windowsservercore-ltsc2016, 1.5-windowsservercore-ltsc2016, 1.5-rc-windowsservercore-ltsc2016, rc-windowsservercore-ltsc2016
 SharedTags: 1.5.0-rc1, 1.5.0, 1.5, 1.5-rc, rc
 Architectures: windows-amd64