alpine:3.15 for arangodb 3.9

[KVS85]

Update Alpine base to 3.15 for ArangoDB 3.9. Related to #14607.

[github-actions]

Diff for 111e2bb:

diff --git a/_bashbrew-cat b/_bashbrew-cat
index 3baf9b9..f3283a9 100644
--- a/_bashbrew-cat
+++ b/_bashbrew-cat
@@ -3,7 +3,7 @@ GitRepo: https://github.com/arangodb/arangodb-docker
 GitFetch: refs/heads/official
 
 Tags: 3.9, 3.9.10
-GitCommit: 04479ca0b7f52b6f23f3739eae6994f4875990f2
+GitCommit: 83dcd50e8af2210c1315074d8c9260b9ff572e9f
 Directory: alpine/3.9.10
 
 Tags: 3.10, 3.10.6, latest
diff --git a/arangodb_3.9.10/Dockerfile b/arangodb_3.9.10/Dockerfile
index 3956a5b..6a8f88a 100644
--- a/arangodb_3.9.10/Dockerfile
+++ b/arangodb_3.9.10/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.14
+FROM alpine:3.15
 MAINTAINER Frank Celler <info@arangodb.com>
 
 ENV ARANGO_VERSION 3.9.10

Relevant Maintainers:

• arangodb: @fceller @dothebart @KVS85