Update mariadb

Changes:

- https://github.com/docker-library/mariadb/commit/b263d8d: Merge pull request https://github.com/docker-library/mariadb/pull/277 from infosiftr/10.5
- https://github.com/docker-library/mariadb/commit/9372a0d: Add 10.5.1 (first 10.5 beta)

library/mariadb

@@ -4,6 +4,11 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/mariadb.git
 
+Tags: 10.5.1-bionic, 10.5-bionic, beta-bionic, 10.5.1, 10.5, beta
+Architectures: amd64, arm64v8, ppc64le
+GitCommit: 9372a0dfecdce6bb860de28aa93cf6f1bacd392e
+Directory: 10.5
+
 Tags: 10.4.12-bionic, 10.4-bionic, 10-bionic, bionic, 10.4.12, 10.4, 10, latest
 Architectures: amd64, arm64v8, ppc64le
 GitCommit: c895fa579e99a69667e14b50c4b9bdb85d4854fe