bump to use latest master branch of steel again, fixes msrv issue

Cargo.lock

@@ -2593,7 +2593,7 @@ checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 [[package]]
 name = "steel-core"
 version = "0.5.0"
-source = "git+https://github.com/mattwparas/steel.git#78514fac9b22a82a98997e7c928224ddb65e63f7"
+source = "git+https://github.com/mattwparas/steel.git#45f582560445da5faaaa19098c5b50e7f872c10e"
 dependencies = [
  "abi_stable",
  "anyhow",
@@ -2630,7 +2630,7 @@ dependencies = [
 [[package]]
 name = "steel-derive"
 version = "0.4.0"
-source = "git+https://github.com/mattwparas/steel.git#78514fac9b22a82a98997e7c928224ddb65e63f7"
+source = "git+https://github.com/mattwparas/steel.git#45f582560445da5faaaa19098c5b50e7f872c10e"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -2640,7 +2640,7 @@ dependencies = [
 [[package]]
 name = "steel-gen"
 version = "0.2.0"
-source = "git+https://github.com/mattwparas/steel.git#78514fac9b22a82a98997e7c928224ddb65e63f7"
+source = "git+https://github.com/mattwparas/steel.git#45f582560445da5faaaa19098c5b50e7f872c10e"
 dependencies = [
  "codegen",
  "serde",
@@ -2650,7 +2650,7 @@ dependencies = [
 [[package]]
 name = "steel-parser"
 version = "0.4.0"
-source = "git+https://github.com/mattwparas/steel.git#78514fac9b22a82a98997e7c928224ddb65e63f7"
+source = "git+https://github.com/mattwparas/steel.git#45f582560445da5faaaa19098c5b50e7f872c10e"
 dependencies = [
  "logos",
  "num-bigint",