Pin FLTK to 1.3 in homebrew

Homebrew has updated the default version of FLTK to 1.4, which is
causing rendering issues in Dillo. So for now, we build with FLTK 1.3 by
pinning it.

See: Homebrew/homebrew-core#198029
See: #246

.github/workflows/build.yml

@@ -180,7 +180,7 @@ jobs:
       with:
         fetch-depth: 1
     - name: Install dependencies
-      run: brew install autoconf automake fltk
+      run: brew install autoconf automake fltk@1.3
     - name: autogen
       run: ./autogen.sh
     - name: configure
@@ -201,7 +201,7 @@ jobs:
     - name: Remove old OpenSSL 1.1
       run: brew uninstall [email protected]
     - name: Install dependencies
-      run: brew install autoconf automake fltk openssl@3
+      run: brew install autoconf automake fltk@1.3 openssl@3
     - name: autogen
       run: ./autogen.sh
     - name: configure

doc/install.md

@@ -144,7 +144,7 @@ autoconf and automake if you are building Dillo from the git repository.
 They are available in the Homebrew package manager:
 
 ```
-$ brew install autoconf automake fltk
+$ brew install autoconf automake fltk@1.3
 ```
 
 For OpenSSL you can use either 1.1 or 3.X (recommended):