fix(ci): grant callers the permissions their reusable workflows declare (#754)

GitHub refuses these runs at workflow-creation time: `Error calling
workflow ... The workflow is requesting '<perm>', but is only allowed
'<none>'.` A `workflow_call` job must grant a superset of the callee's
declared permissions. This adds the canonical grant (`actions: read`,
`contents: read`, `security-events: write`) that the healthy repos
already carry.

Author: hyperpolymath

.github/workflows/mirror.yml

@@ -14,3 +14,7 @@ jobs:
   mirror:
     uses: hyperpolymath/standards/.github/workflows/mirror-reusable.yml@571cc734cd69fb846032ec77a662aa8ee4fc32cd
     secrets: inherit
+      permissions:
+        actions: read
+        contents: read
+        security-events: write

.github/workflows/scorecard.yml

@@ -15,6 +15,7 @@ jobs:
   analysis:
     uses: hyperpolymath/standards/.github/workflows/scorecard-reusable.yml@571cc734cd69fb846032ec77a662aa8ee4fc32cd
     permissions:
+      actions: read
       contents: read
       security-events: write
       id-token: write

.github/workflows/spark-theatre-gate.yml

@@ -31,3 +31,7 @@ jobs:
     with:
       paths: "."
       enforce_zero_contract: false
+      permissions:
+        actions: read
+        contents: read
+        security-events: write