Update CI after 5.4 release

Author: voodoos

.github/workflows/build-and-test.yml

@@ -49,7 +49,7 @@ jobs:
 
       # Remove this pin once a compatible version of Merlin has been released
       - name: Pin dev Merlin
-        run: opam --cli=2.1 pin --with-version=5.6-504 https://github.com/voodoos/merlin.git#504-rebase
+        run: opam --cli=2.1 pin --with-version=5.6-504 https://github.com/voodoos/merlin.git#main
 
       - name: Build and install dependencies
         run: opam install .
@@ -90,7 +90,7 @@ jobs:
 
       # Remove this pin once a compatible version of Merlin has been released
       - name: Pin dev Merlin
-        run: opam --cli=2.1 pin --with-version=5.6-504 https://github.com/voodoos/merlin.git#504-rebase
+        run: opam --cli=2.1 pin --with-version=5.6-504 https://github.com/voodoos/merlin.git#main
 
       - name: Install dependencies
         run: |