[ci] Change to string type (#32980)

to no one's surprise, the `number` type appears to be cursed in GH
actions for workflow dispatch. switch to string

.github/workflows/compiler_prereleases.yml

@@ -18,7 +18,7 @@ on:
         type: string
       tag_version:
         required: false
-        type: number
+        type: string
     secrets:
       NPM_TOKEN:
         required: true

.github/workflows/compiler_prereleases_manual.yml

@@ -16,7 +16,7 @@ on:
         type: string
       tag_version:
         required: false
-        type: number
+        type: string
 
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