Remove softfp build

The softfp build hasn't been updated in ages and people seem to have
switched to the softfp fork. We should probably remove it, so we can
build the vitasdk containers again. Right now the schedule is paused
because of failures.

Author: sharkwouter

.github/workflows/docker.yml

@@ -22,8 +22,6 @@ jobs:
             tags: vitasdk/vitasdk:latest
           - context: ./non-root
             tags: vitasdk/vitasdk:non-root
-          - context: ./softfp
-            tags: vitasdk/vitasdk-softfp:latest
 
     steps:
     - uses: actions/checkout@v3