Bump nix from 0.20.0 to 0.20.2

Bumps [nix](https://github.com/nix-rust/nix) from 0.20.0 to 0.20.2.
- [Release notes](https://github.com/nix-rust/nix/releases)
- [Changelog](https://github.com/nix-rust/nix/blob/v0.20.2/CHANGELOG.md)
- [Commits](https://github.com/nix-rust/nix/compare/v0.20.0...v0.20.2)

---
updated-dependencies:
- dependency-name: nix
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.lock

@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "abortable_parser"
 version = "0.2.3"
@@ -234,9 +236,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.89"
+version = "0.2.126"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "538c092e5586f4cdd7dd8078c4a79220e3e168880218124dcbce860f0ea938c6"
+checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
 
 [[package]]
 name = "linked-hash-map"
@@ -259,6 +261,15 @@ version = "2.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 
+[[package]]
+name = "memoffset"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aa361d4faea93603064a027415f07bd8e1d5c88c9fbf68bf56a285428fd79ce"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "nibble_vec"
 version = "0.1.0"
@@ -270,14 +281,15 @@ dependencies = [
 
 [[package]]
 name = "nix"
-version = "0.20.0"
+version = "0.20.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa9b4819da1bc61c0ea48b63b7bc8604064dd43013e7cc325df098d49cd7c18a"
+checksum = "f5e06129fb611568ef4e868c14b326274959aa70ff7776e9d55323531c374945"
 dependencies = [
  "bitflags",
  "cc",
  "cfg-if",
  "libc",
+ "memoffset",
 ]
 
 [[package]]