'fmt' builds with GHC 8.6 now

As well as some other packages that depend on haskell-src-meta.

build-constraints.yaml

@@ -3857,7 +3857,6 @@ packages:
         - flac < 0
         - flac-picture < 0
         - flow < 0
-        - fmt < 0
         - fold-debounce-conduit < 0
         - friday < 0
         - friday-juicypixels < 0
@@ -3898,7 +3897,6 @@ packages:
         - haskell-lsp < 0
         - haskell-lsp-types < 0
         - haskell-spacegoo < 0
-        - haskell-src-meta < 0
         - haskell-tools-ast < 0
         - haskell-tools-backend-ghc < 0
         - haskell-tools-builtin-refactorings < 0
@@ -3969,7 +3967,6 @@ packages:
         - influxdb < 0
         - inline-java < 0
         - inliterate < 0
-        - interpolate < 0
         - interpolatedstring-perl6 < 0
         - invertible < 0
         - invertible-grammar < 0