use main tags for workflows

Author: nvaytet

.github/workflows/pr_and_main.yml

@@ -12,4 +12,4 @@ concurrency:
 
 jobs:
   build:
-    uses: scipp/ess/.github/workflows/build.yml@fix_anaconda_upload
+    uses: scipp/ess/.github/workflows/build.yml@main

.github/workflows/weekly_and_release.yml

@@ -9,8 +9,8 @@ on:
 
 jobs:
   build:
-    uses: scipp/ess/.github/workflows/build.yml@fix_anaconda_upload
+    uses: scipp/ess/.github/workflows/build.yml@main
 
   deploy:
     needs: build
-    uses: scipp/ess/.github/workflows/deploy.yml@fix_anaconda_upload
+    uses: scipp/ess/.github/workflows/deploy.yml@main