Change branching to "main is the future release, branches are for servicing" (#18730)

* Stop auto servicing from main

* Update VS insertion mapping

* Update Versions.props

* Update Versions.props

* Update FSharp.Compiler.Service.fsproj

Author: T-Gro

.config/service-branch-merge.json

@@ -12,10 +12,6 @@
         "release/dev17.14": {
             "MergeToBranch": "main",
             "ExtraSwitches": "-QuietComments"
-        },
-        "main": {
-            "MergeToBranch": "release/dev18.0",
-            "ExtraSwitches": "-QuietComments"
         }
     }
 }

azure-pipelines.yml

@@ -26,14 +26,12 @@ trigger:
 
 variables:
   # Release branch for F#
-  # Should be 'current' release branch name, i.e. 'release/dev17.10' in dotnet/fsharp/refs/heads/main, 'release/dev17.10' in dotnet/fsharp/refs/heads/release/dev17.10 and 'release/dev17.9' in dotnet/fsharp/refs/heads/release/dev17.9
-  # Should **never** be 'main' in dotnet/fsharp/refs/heads/main, since it will start inserting to VS twice.
+  # The future "product" gets developed in main, so should be main in main.
+  # When servicing branch gets created, this should maintain the mapping between F# servicing and VS servicing branches
   - name: FSharpReleaseBranchName
-    value: release/dev18.0
+    value: main
   # VS Insertion branch name (NOT the same as F# branch)
-  # Should be previous release branch or 'main' in 'main' and 'main' in release branch
-  # (since for all *new* release branches we insert into VS main and for all *previous* releases we insert into corresponding VS release),
-  # i.e. 'rel/d17.9' *or* 'main' in dotnet/fsharp/refs/heads/main and 'main' in F# dotnet/fsharp/refs/heads/release/dev17.10 (latest release branch)
+  # ( for main we insert into VS main and for all *previous* releases we insert into corresponding VS release),
   - name: VSInsertionTargetBranchName
     value: main
   - name: _TeamName
@@ -87,7 +85,7 @@ extends:
       #-------------------------------------------------------------------------------------------------------------------#
       #                                                  Signed build                                                     #
       #-------------------------------------------------------------------------------------------------------------------#
-      # Localization: we only run it for specific release branches
+      # Localization: we only run it for main
       - ${{ if eq(variables['Build.SourceBranch'], 'refs/heads/main') }}:
         - template: /eng/common/templates-official/job/onelocbuild.yml@self
           parameters:

eng/Versions.props

@@ -11,7 +11,7 @@
   <PropertyGroup>
     <!-- Don't use the built in support for pre-release iteration. The nuget repack task doesn't support
          the iteration format at the moment. https://github.com/dotnet/arcade/issues/15919 -->
-    <FSharpPreReleaseIteration>6</FSharpPreReleaseIteration>
+    <FSharpPreReleaseIteration>7</FSharpPreReleaseIteration>
     <PreReleaseVersionLabel>preview$(FSharpPreReleaseIteration)</PreReleaseVersionLabel>
     <!-- These have to be in sync with latest release branch -->
     <!-- F# Version components -->