Update dependency platform-api to v3.9.0

Author: renovate[bot]

Gemfile.lock

@@ -261,7 +261,6 @@ GEM
     drb (2.2.3)
     erb (6.0.4)
     erubi (1.13.1)
-    erubis (2.7.0)
     eu_central_bank (2.0.0)
       bigdecimal
       money (~> 7.0)
@@ -312,12 +311,11 @@ GEM
       tilt
     heapy (0.2.0)
       thor
-    heroics (0.1.3)
+    heroics (0.1.4)
       base64
-      erubis (~> 2.0)
       excon
+      json
       moneta
-      multi_json (>= 1.9.2)
       webrick
     holidays (8.8.0)
     i18n (1.14.8)
@@ -395,7 +393,6 @@ GEM
       money (~> 7.0)
       railties (>= 7.0)
     msgpack (1.8.0)
-    multi_json (1.15.0)
     mutex_m (0.3.0)
     mysql2 (0.5.7)
       bigdecimal
@@ -435,7 +432,7 @@ GEM
       activerecord (>= 6.1)
       activesupport (>= 6.1)
     phonelib (0.10.18)
-    platform-api (3.8.0)
+    platform-api (3.9.0)
       heroics (~> 0.1.1)
       moneta (~> 1.0.0)
       rate_throttle_client (~> 0.1.0)