Update http4s-client, ... to 1.0.0-M38 in main (#799)

Co-authored-by: http4s-steward[bot] <106843772+http4s-steward[bot]@users.noreply.github.com>

Author: http4s-steward[bot]

build.sbt

@@ -38,7 +38,7 @@ val catsV = "2.9.0"
 val catsEffectV = "3.4.4"
 val fs2V = "3.4.0"
 val scodecV = "1.1.34"
-val http4sV = "1.0.0-M37"
+val http4sV = "1.0.0-M38"
 val reactiveStreamsV = "1.0.4"
 val vaultV = "3.5.0"
 val caseInsensitiveV = "1.3.0"