Set the token permissions to contents: read

This fixes a number of code scanning alerts such as
https://github.com/liblouis/liblouis/security/code-scanning/46.

The fix was provided by https://app.stepsecurity.io/

Two alerts were not fixed as the stepsecurity tool did not provide the
usual fix by setting the token permission. Instead it suggested to use
a "Harden Runner". ATM I do not understand the implications of that so
I postponed this.

So for mingw.yml and for emscripten.yml the alerts remain.
diff --git a/.github/workflows/check-format.yml b/.github/workflows/check-format.yml
index fdbf01c..90a31dd 100644
--- a/.github/workflows/check-format.yml
+++ b/.github/workflows/check-format.yml
@@ -10,6 +10,9 @@
   pull_request:
     branches: [ master ]
 
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
 jobs:
   check-format:
     name: Check the code formatting
diff --git a/.github/workflows/check-table-license.yml b/.github/workflows/check-table-license.yml
index 14a7447..2610aa1 100644
--- a/.github/workflows/check-table-license.yml
+++ b/.github/workflows/check-table-license.yml
@@ -10,6 +10,9 @@
   pull_request:
     branches: [ master ]
 
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
 jobs:
   check-licenses:
     name: Check the license of the tables
diff --git a/.github/workflows/cifuzz.yml b/.github/workflows/cifuzz.yml
index 47539d1..24bde9b 100644
--- a/.github/workflows/cifuzz.yml
+++ b/.github/workflows/cifuzz.yml
@@ -8,6 +8,10 @@
 # servers.
 name: CIFuzz
 on: [pull_request]
+
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
 jobs:
   Fuzzing:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/fuzzing.yml b/.github/workflows/fuzzing.yml
index 4492e28..44982e7 100644
--- a/.github/workflows/fuzzing.yml
+++ b/.github/workflows/fuzzing.yml
@@ -5,6 +5,9 @@
   schedule:
     - cron: "0 4 * * 1"
 
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
 jobs:
   build:
     name: Build with ${{ matrix.ucs }}
diff --git a/.github/workflows/macro.yml b/.github/workflows/macro.yml
index f87928d..fb9db13 100644
--- a/.github/workflows/macro.yml
+++ b/.github/workflows/macro.yml
@@ -10,6 +10,9 @@
   pull_request:
     branches: [ master ]
 
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
 jobs:
   build:
     name: Test macro feature
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index cd3e521..b1967ea 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -10,6 +10,9 @@
   pull_request:
     branches: [ master ]
 
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
 jobs:
   build:
     name: Build with ${{ matrix.ucs }}
diff --git a/.github/workflows/metadata.yml b/.github/workflows/metadata.yml
index a55ad9f..fc14251 100644
--- a/.github/workflows/metadata.yml
+++ b/.github/workflows/metadata.yml
@@ -9,6 +9,9 @@
   pull_request:
     branches: [ master ]
 
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
 jobs:
   metadata-test:
     name: Build and check the metadta
diff --git a/.github/workflows/sanitizer.yml b/.github/workflows/sanitizer.yml
index 868ecf3..0554468 100644
--- a/.github/workflows/sanitizer.yml
+++ b/.github/workflows/sanitizer.yml
@@ -14,6 +14,9 @@
       - '**.h'
       - '**.c'
 
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
 jobs:
   build:
     runs-on: ubuntu-latest