dapp/seth: fix --use and --nix-use

According to the new CLI docs, by using --expr we're saying that the
installable (in our case `out`) is an attribute in the attribute set
that the expression evaluates to.

So it should always be there, and therefore callers don't need to add
it.

src/dapp/libexec/dapp/dapp---nix-run

@@ -16,4 +16,4 @@ have() { command -v "$1" >/dev/null; }
 
 expr="$1"; shift
 
-nix run --impure --expr "with import $DAPPTOOLS {}; $expr" -- "$@"
+nix run --impure --expr "with import $DAPPTOOLS {}; $expr" out -- "$@"

src/dapp/libexec/dapp/dapp---use

@@ -59,7 +59,7 @@ shift
 [[ "$#" -gt 0 ]] || usage
 
 if [[ -z "$bin" ]]; then
-  dapp --nix-run "dapp.override {solc = pkgs.runCommand \"solc\" { } \"mkdir -p \$out/bin; ln -s \${solc-static-versions.${solc//[-.]/_}}/bin/${solc} \$out/bin/solc\";}" out "$@"
+  dapp --nix-run "dapp.override {solc = pkgs.runCommand \"solc\" { } \"mkdir -p \$out/bin; ln -s \${solc-static-versions.${solc//[-.]/_}}/bin/${solc} \$out/bin/solc\";}" "$@"
 else
   set -e
   SOLCBIN="$(realpath -e "${bin}")"

src/seth/libexec/seth/seth---nix-run

@@ -16,4 +16,4 @@ have() { command -v "$1" >/dev/null; }
 
 expr="$1"; shift
 
-nix run --impure --expr "with import $DAPPTOOLS {}; $expr" -- "$@"
+nix run --impure --expr "with import $DAPPTOOLS {}; $expr" out -- "$@"

src/seth/libexec/seth/seth---use

@@ -56,7 +56,7 @@ shift
 [[ "$#" -gt 0 ]] || usage
 
 if [[ -z "$bin" ]]; then
-  seth --nix-run "seth.override {solc = pkgs.runCommand \"solc\" { } \"mkdir -p \$out/bin; ln -s \${solc-static-versions.${solc//[-.]/_}}/bin/${solc} \$out/bin/solc\";}" out "$@"
+  seth --nix-run "seth.override {solc = pkgs.runCommand \"solc\" { } \"mkdir -p \$out/bin; ln -s \${solc-static-versions.${solc//[-.]/_}}/bin/${solc} \$out/bin/solc\";}" "$@"
 else
   set -e
   SOLCBIN="$(realpath -e "${bin}")"