gha: reduce execution frequency (on cheap runner)

Since this runs on every push to the target branches, it is incurring
excessive CI minutes usage. Only release on tagged commits to reduce
consumption

Also, for the arm variant, use 2-core VMs

Signed-off-by: Ivo Jimenez <[email protected]>

.github/workflows/release-rp-storage-tool.yml

@@ -2,19 +2,8 @@ name: Release rp-storage-tool
 
 on:
   push:
-    branches:
-      - dev
-      - 'v*'
     tags:
       - 'v*'
-  pull_request:
-    paths:
-      - 'tools/rp_storage_tool/**'
-      - 'tests/docker/Dockerfile'
-      - 'tests/docker/ducktape-deps/rust'
-      - 'tests/docker/ducktape-deps/rp-storage-tool'
-      - '.github/workflows/release-rp-storage-tool.yml'
-
 
 jobs:
   release-rp-storage-tool:
@@ -26,7 +15,7 @@ jobs:
           - release_for: linux-amd64
             os: ubuntu-latest
           - release_for: linux-arm64
-            os: ubuntu-latest-4-arm64
+            os: ubuntu-latest-2-arm64
     runs-on: ${{ matrix.platform.os }}
     steps:
       - name: configure aws credentials