ci: remove workflow permissions

Closing some security gaps.

Author: indygreg

.github/workflows/anaconda.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   linux:
     strategy:

.github/workflows/external-zstd.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   linux:
     runs-on: 'ubuntu-22.04'

.github/workflows/pypy.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   wheel:
     strategy:

.github/workflows/ruff.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   ruff:
     runs-on: ubuntu-latest

.github/workflows/sdist.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   sdist:
     runs-on: 'ubuntu-22.04'

.github/workflows/sphinx.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   sphinx:
     runs-on: ubuntu-24.04

.github/workflows/test.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   test:
     strategy:

.github/workflows/typing.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   mypy:
     strategy:

.github/workflows/wheel.yml

@@ -3,6 +3,7 @@ on:
   pull_request:
   schedule:
     - cron: '30 13 * * *'
+permissions: { }
 jobs:
   linux:
     strategy: