Point dashboard to the main branch (#1881)

so that they always import the latest version

Author: mkuratczyk

observability/grafana/dashboards/erlang-distribution.yml

@@ -7,4 +7,4 @@ metadata:
     grafana_dashboard: "true"
 data:
   # https://grafana.com/grafana/dashboards/11352
-  erlang-distribution-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/e57c579d1a71b283469defdd0d6d45313e6d6daf/deps/rabbitmq_prometheus/docker/grafana/dashboards/Erlang-Distribution.json"
+  erlang-distribution-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/main/deps/rabbitmq_prometheus/docker/grafana/dashboards/Erlang-Distribution.json"

observability/grafana/dashboards/erlang-distributions-compare.yml

@@ -7,4 +7,4 @@ metadata:
     grafana_dashboard: "true"
 data:
   # https://grafana.com/grafana/dashboards/11350
-  erlang-memory-allocators-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/e57c579d1a71b283469defdd0d6d45313e6d6daf/deps/rabbitmq_prometheus/docker/grafana/dashboards/Erlang-Memory-Allocators.json"
+  erlang-memory-allocators-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/main/deps/rabbitmq_prometheus/docker/grafana/dashboards/Erlang-Memory-Allocators.json"

observability/grafana/dashboards/erlang-memory-allocators.yml

@@ -7,4 +7,4 @@ metadata:
     grafana_dashboard: "true"
 data:
   # https://grafana.com/grafana/dashboards/10991
-  rabbitmq-overview-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/e57c579d1a71b283469defdd0d6d45313e6d6daf/deps/rabbitmq_prometheus/docker/grafana/dashboards/RabbitMQ-Overview.json"
+  rabbitmq-overview-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/main/deps/rabbitmq_prometheus/docker/grafana/dashboards/RabbitMQ-Overview.json"

observability/grafana/dashboards/rabbitmq-overview.yml

@@ -7,4 +7,4 @@ metadata:
     grafana_dashboard: "true"
 data:
   # https://grafana.com/grafana/dashboards/11340
-  rabbitmq-quorum-queues-raft-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/e57c579d1a71b283469defdd0d6d45313e6d6daf/deps/rabbitmq_prometheus/docker/grafana/dashboards/RabbitMQ-Quorum-Queues-Raft.json"
+  rabbitmq-quorum-queues-raft-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/main/deps/rabbitmq_prometheus/docker/grafana/dashboards/RabbitMQ-Quorum-Queues-Raft.json"

observability/grafana/dashboards/rabbitmq-quorum-queues-raft.yml

@@ -7,4 +7,4 @@ metadata:
     grafana_dashboard: "true"
 data:
   # https://grafana.com/grafana/dashboards/14798
-  rabbitmq-stream-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/e57c579d1a71b283469defdd0d6d45313e6d6daf/deps/rabbitmq_prometheus/docker/grafana/dashboards/RabbitMQ-Stream.json"
+  rabbitmq-stream-dashboard.json.url: "https://github.com/rabbitmq/rabbitmq-server/raw/main/deps/rabbitmq_prometheus/docker/grafana/dashboards/RabbitMQ-Stream.json"