BREAKING: replace custom build scripts with nix

General:
- Switched to yarn to better work with nix-based tooling
- Switched package system to use nix. This stops double dependencies and slow cloud compile times, while providing more compile/runtime support to the Nix project
- Removed container builder in favor of internal container tooling
- Package versions no-longer need to be SemVer compliant
- Removed "piston package spec" files, replaced with nix-flake based runtimes
- Exported nosocket and piston-api as packages within the nix-flake
- Removed repo container
- Switched docker building to nix-based container outputting
- Removed docker compose as this is a single container
- Removed package commands from CLI

Packages:
- Move bash, clojure, cobol, node, python2, python3 to new format
- Remainder of packages still need to be moved

v2 API:
- Removed "version" specifier. To select specific versions, use the v3 api
- Removed "/package" endpoints as this doesn't work with the new nix-based system

v3 API:
- Duplicate of v2 API, except instead of passing in a language name an ID is used intead.

api/src/nosocket/nosocket.c

@@ -1,62 +0,0 @@
-/*
-nosocket.c
-
-Disables access to the `socket` syscall and runs a program provided as the first
-commandline argument.
-*/
-#include <stdio.h>
-#include <errno.h>
-#include <unistd.h>
-#include <sys/prctl.h>
-#include <seccomp.h>
-
-int main(int argc, char *argv[])
-{
-    // Disallow any new capabilities from being added
-    prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
-
-    // SCMP_ACT_ALLOW lets the filter have no effect on syscalls not matching a
-    // configured filter rule (allow all by default)
-    scmp_filter_ctx ctx = seccomp_init(SCMP_ACT_ALLOW);
-    if (!ctx)
-    {
-        fprintf(stderr, "Unable to initialize seccomp filter context\n");
-        return 1;
-    }
-
-    // Add 32 bit and 64 bit architectures to seccomp filter
-    int rc;
-    uint32_t arch[] = {SCMP_ARCH_X86_64, SCMP_ARCH_X86, SCMP_ARCH_X32};
-    // We first remove the existing arch, otherwise our subsequent call to add
-    // it will fail
-    seccomp_arch_remove(ctx, seccomp_arch_native());
-    for (int i = 0; i < sizeof(arch) / sizeof(arch[0]); i++)
-    {
-        rc = seccomp_arch_add(ctx, arch[i]);
-        if (rc != 0)
-        {
-            fprintf(stderr, "Unable to add arch: %d\n", arch[i]);
-            return 1;
-        }
-    }
-
-    // Add a seccomp rule to the syscall blacklist - blacklist the socket syscall
-    if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(EACCES), SCMP_SYS(socket), 0) < 0)
-    {
-        fprintf(stderr, "Unable to add seccomp rule to context\n");
-        return 1;
-    }
-
-#ifdef DEBUG
-    seccomp_export_pfc(ctx, 0);
-#endif
-
-    if (argc < 2)
-    {
-        fprintf(stderr, "Usage %s: %s <program name> <arguments>\n", argv[0], argv[0]);
-        return 1;
-    }
-    seccomp_load(ctx);
-    execvp(argv[1], argv + 1);
-    return 1;
-}