ci: don't install pkg-config explicitly

.github/workflows/cleanup.sh

@@ -1,6 +0,0 @@
-#!/bin/bash
-set -e
-
-if pkg=$(brew list | grep -E "pkg-config"); then
-    brew uninstall "$pkg" || true
-fi

.github/workflows/doc.yml

@@ -16,10 +16,10 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: '20'
-          
+
       - name: Install embedme
         run: npm install -g embedme
-        
+
       - name: Verify README.md embedded code
         run: npx embedme --verify README.md
 
@@ -32,7 +32,7 @@ jobs:
     runs-on: ${{matrix.os}}
     steps:
       - uses: actions/checkout@v4
-        
+
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
@@ -43,7 +43,6 @@ jobs:
         run: |
           set -e
           set -x
-          bash .github/workflows/cleanup.sh
           source doc/_readme/scripts/install_macos.sh
 
       - name: Install dependencies on Ubuntu

.github/workflows/go.yml

@@ -41,9 +41,8 @@ jobs:
       - name: Install dependencies
         if: startsWith(matrix.os, 'macos')
         run: |
-          bash .github/workflows/cleanup.sh
           brew update
-          brew install llvm@${{matrix.llvm}} pkg-config bdw-gc openssl libffi
+          brew install llvm@${{matrix.llvm}} bdw-gc openssl libffi
           echo "$(brew --prefix llvm@${{matrix.llvm}})/bin" >> $GITHUB_PATH
           echo "PKG_CONFIG_PATH=/opt/homebrew/opt/libffi/lib/pkgconfig" >> $GITHUB_ENV