fix(Makefile): don't export DATABASE_URL from .env

Kept running into issues where if I tried to compile the project from
the Makefile I would get a bunch of errors from SQLx but if I ran the
exact same commands in the shell it would be fine. Apparently the
problem was that SQLx expects the DATABASE_URL var to be a regular shell
variable, which it's not if it's exported by Make.

The fix is to not export the Make var and now everything works.

Author: realprogrammersusevim

Makefile

@@ -1,16 +1,17 @@
 ifneq (,$(wildcard ./.env))
 	include .env
   export
+	unexport DATABASE_URL # Exporting this causes sqlx to fail during compilation
 endif
 
 BUILD_DIR="target/x86_64-unknown-linux-gnu/release"
 BIN_NAME="jonathansm"
 
 .PHONY: all pi mac test clean deploy
 
-all: pi mac
+all: linux mac
 
-pi:
+linux:
 	cargo build --release --target=x86_64-unknown-linux-gnu
 
 mac: